diff --git a/RoboFile.php b/RoboFile.php
index a2ad1421bd..1540b311f0 100644
--- a/RoboFile.php
+++ b/RoboFile.php
@@ -17,7 +17,7 @@ class RoboFile extends \Robo\Tasks {
     $dotenv->load();
   }
 
-  function install() {
+  public function install() {
     return $this->taskExecStack()
       ->stopOnFail()
       ->exec('./tools/vendor/composer.phar install')
@@ -25,7 +25,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function update() {
+  public function update() {
     return $this->taskExecStack()
       ->stopOnFail()
       ->exec('./tools/vendor/composer.phar update')
@@ -33,7 +33,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function watch() {
+  public function watch() {
     $this->say('Warning: this lints and compiles all files, not just the changed one. Use separate tasks watch:js and watch:css for faster and more efficient watching.');
     $css_files = $this->rsearch('assets/css/src/', ['scss']);
     $js_files = $this->rsearch('assets/js/src/', ['js', 'jsx']);
@@ -48,7 +48,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function watchCss() {
+  public function watchCss() {
     $css_files = $this->rsearch('assets/css/src/', ['scss']);
     $this->taskWatch()
       ->monitor($css_files, function($changedFile) {
@@ -63,11 +63,11 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function watchJs() {
+  public function watchJs() {
     $this->_exec('./node_modules/webpack/bin/webpack.js --watch');
   }
 
-  function compileAll($opts = ['env' => null]) {
+  public function compileAll($opts = ['env' => null]) {
     $collection = $this->collectionBuilder();
     $collection->addCode(function() use ($opts) {
       return call_user_func([$this, 'compileJs'], $opts);
@@ -78,7 +78,7 @@ class RoboFile extends \Robo\Tasks {
     return $collection->run();
   }
 
-  function compileJs($opts = ['env' => null]) {
+  public function compileJs($opts = ['env' => null]) {
     if (!is_dir('assets/dist/js')) {
       mkdir('assets/dist/js', 0777, true);
     }
@@ -88,7 +88,7 @@ class RoboFile extends \Robo\Tasks {
     return $this->_exec($env . ' ./node_modules/webpack/bin/webpack.js --bail');
   }
 
-  function compileCss($opts = ['env' => null]) {
+  public function compileCss($opts = ['env' => null]) {
     if (!is_dir('assets/dist/css')) {
       mkdir('assets/dist/css', 0777, true);
     }
@@ -119,33 +119,33 @@ class RoboFile extends \Robo\Tasks {
     return $compilation_result;
   }
 
-  function translationsInit() {
+  public function translationsInit() {
     // Define WP_TRANSIFEX_API_TOKEN env. variable
     return $this->_exec('./tasks/transifex_init.sh');
   }
 
-  function translationsBuild() {
+  public function translationsBuild() {
     return $this->_exec('./node_modules/.bin/grunt makepot' .
       ' --gruntfile=' . __DIR__ . '/tasks/makepot/makepot.js' .
       ' --base_path=' . __DIR__
     );
   }
 
-  function translationsPack() {
+  public function translationsPack() {
     return $this->collectionBuilder()
       ->addCode([$this, 'translationsInit'])
       ->taskExec('./tasks/pack_translations.sh')
       ->run();
   }
 
-  function translationsPush() {
+  public function translationsPush() {
     return $this->collectionBuilder()
       ->addCode([$this, 'translationsInit'])
       ->taskExec('tx push -s')
       ->run();
   }
 
-  function testUnit(array $opts=['file' => null, 'xml' => false, 'multisite' => false, 'debug' => false]) {
+  public function testUnit(array $opts=['file' => null, 'xml' => false, 'multisite' => false, 'debug' => false]) {
     $command = 'vendor/bin/codecept run unit';
 
     if ($opts['file']) {
@@ -163,7 +163,7 @@ class RoboFile extends \Robo\Tasks {
     return $this->_exec($command);
   }
 
-  function testIntegration(array $opts=['file' => null, 'xml' => false, 'multisite' => false, 'debug' => false]) {
+  public function testIntegration(array $opts=['file' => null, 'xml' => false, 'multisite' => false, 'debug' => false]) {
     $command = 'vendor/bin/codecept run integration';
 
     if ($opts['multisite']) {
@@ -185,11 +185,11 @@ class RoboFile extends \Robo\Tasks {
     return $this->_exec($command);
   }
 
-  function testMultisiteIntegration($opts=['file' => null, 'xml' => false, 'multisite' => true]) {
+  public function testMultisiteIntegration($opts=['file' => null, 'xml' => false, 'multisite' => true]) {
     return $this->testIntegration($opts);
   }
 
-  function testCoverage($opts=['file' => null, 'xml' => false]) {
+  public function testCoverage($opts=['file' => null, 'xml' => false]) {
     $command = join(' ', [
       'vendor/bin/codecept run -s acceptance',
       (($opts['file']) ? $opts['file'] : ''),
@@ -204,7 +204,7 @@ class RoboFile extends \Robo\Tasks {
     return $this->execWithXDebug($command);
   }
 
-  function testNewsletterEditor($xml_output_file = null) {
+  public function testNewsletterEditor($xml_output_file = null) {
     $this->compileJs();
 
     $command = join(' ', [
@@ -223,7 +223,7 @@ class RoboFile extends \Robo\Tasks {
     return $this->_exec($command);
   }
 
-  function testJavascript($xml_output_file = null) {
+  public function testJavascript($xml_output_file = null) {
     $command = './node_modules/.bin/mocha --require @babel/register tests/javascript/**/*.spec.js';
 
     if (!empty($xml_output_file)) {
@@ -236,22 +236,22 @@ class RoboFile extends \Robo\Tasks {
     return $this->_exec($command);
   }
 
-  function securityComposer() {
+  public function securityComposer() {
     return $this->collectionBuilder()
       ->taskExec('vendor/bin/security-checker security:check --format=simple')
       ->taskExec('vendor/bin/security-checker security:check --format=simple prefixer/composer.lock')
       ->run();
   }
 
-  function testDebugUnit($opts=['file' => null, 'xml' => false, 'debug' => true]) {
+  public function testDebugUnit($opts=['file' => null, 'xml' => false, 'debug' => true]) {
     return $this->testUnit($opts);
   }
 
-  function testDebugIntegration($opts=['file' => null, 'xml' => false, 'debug' => true]) {
+  public function testDebugIntegration($opts=['file' => null, 'xml' => false, 'debug' => true]) {
     return $this->testIntegration($opts);
   }
 
-  function testAcceptance($opts=['file' => null, 'skip-deps' => false, 'timeout' => null]) {
+  public function testAcceptance($opts=['file' => null, 'skip-deps' => false, 'timeout' => null]) {
     return $this->taskExec(
       'COMPOSE_HTTP_TIMEOUT=200 docker-compose run ' .
       ($opts['skip-deps'] ? '-e SKIP_DEPS=1 ' : '') .
@@ -261,7 +261,7 @@ class RoboFile extends \Robo\Tasks {
     )->dir(__DIR__ . '/tests/docker')->run();
   }
 
-  function testAcceptanceMultisite($opts=['file' => null, 'skip-deps' => false, 'timeout' => null]) {
+  public function testAcceptanceMultisite($opts=['file' => null, 'skip-deps' => false, 'timeout' => null]) {
     return $this->taskExec(
       'COMPOSE_HTTP_TIMEOUT=200 docker-compose run ' .
       ($opts['skip-deps'] ? '-e SKIP_DEPS=1 ' : '') .
@@ -272,23 +272,23 @@ class RoboFile extends \Robo\Tasks {
     )->dir(__DIR__ . '/tests/docker')->run();
   }
 
-  function deleteDocker() {
+  public function deleteDocker() {
     return $this->taskExec(
       'docker-compose down -v --remove-orphans --rmi all'
     )->dir(__DIR__ . '/tests/docker')->run();
   }
 
-  function testFailedUnit() {
+  public function testFailedUnit() {
     $this->_exec('vendor/bin/codecept build');
     return $this->_exec('vendor/bin/codecept run unit -g failed');
   }
 
-  function testFailedIntegration() {
+  public function testFailedIntegration() {
     $this->_exec('vendor/bin/codecept build');
     return $this->_exec('vendor/bin/codecept run integration -g failed');
   }
 
-  function containerDump() {
+  public function containerDump() {
     define('ABSPATH', getenv('WP_ROOT') . '/');
     if (!file_exists(ABSPATH . 'wp-config.php')) {
       $this->yell('WP_ROOT env variable does not contain valid path to wordpress root.', 40, 'red');
@@ -313,7 +313,7 @@ class RoboFile extends \Robo\Tasks {
     );
   }
 
-  function doctrineGenerateMetadata() {
+  public function doctrineGenerateMetadata() {
     $doctrine_metadata_dir = \MailPoet\Doctrine\ConfigurationFactory::METADATA_DIR;
     $validator_metadata_dir = \MailPoet\Doctrine\Validator\ValidatorFactory::METADATA_DIR;
     $this->_exec("rm -rf $doctrine_metadata_dir");
@@ -334,7 +334,7 @@ class RoboFile extends \Robo\Tasks {
     $this->say("Validator metadata generated to: $validator_metadata_dir");
   }
 
-  function doctrineGenerateProxies() {
+  public function doctrineGenerateProxies() {
     $proxy_dir = \MailPoet\Doctrine\ConfigurationFactory::PROXY_DIR;
     $this->_exec("rm -rf $proxy_dir");
 
@@ -347,7 +347,7 @@ class RoboFile extends \Robo\Tasks {
     $this->say("Doctrine proxies generated to: $proxy_dir");
   }
 
-  function qa() {
+  public function qa() {
     $collection = $this->collectionBuilder();
     $collection->addCode([$this, 'qaLint']);
     $collection->addCode(function() {
@@ -358,19 +358,19 @@ class RoboFile extends \Robo\Tasks {
     return $collection->run();
   }
 
-  function qaLint() {
+  public function qaLint() {
     return $this->_exec('./tasks/code_sniffer/vendor/bin/parallel-lint lib/ tests/ mailpoet.php');
   }
 
-  function qaLintJavascript() {
+  public function qaLintJavascript() {
     return $this->_exec('npm run lint');
   }
 
-  function qaLintCss() {
+  public function qaLintCss() {
     return $this->_exec('npm run stylelint -- "assets/css/src/components/**/*.scss"');
   }
 
-  function qaCodeSniffer($severity='errors') {
+  public function qaCodeSniffer($severity='errors') {
     $severityFlag = $severity === 'all' ? '-w' : '-n';
     $task = implode(' ', [
       './tasks/code_sniffer/vendor/bin/phpcs',
@@ -422,7 +422,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function qaFixFile($filePath) {
+  public function qaFixFile($filePath) {
     if (substr($filePath, -4) === '.php') {
       // fix PHPCS rules
       return $this->collectionBuilder()
@@ -469,7 +469,7 @@ class RoboFile extends \Robo\Tasks {
     }
   }
 
-  function qaPhpstan() {
+  public function qaPhpstan() {
     $dir = __DIR__;
     $task = implode(' ', [
       'WP_ROOT="' . getenv('WP_ROOT') . '"',
@@ -501,7 +501,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function svnCheckout() {
+  public function svnCheckout() {
     $svn_dir = ".mp_svn";
 
     $collection = $this->collectionBuilder();
@@ -524,7 +524,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function svnPushTemplates() {
+  public function svnPushTemplates() {
     $collection = $this->collectionBuilder();
     $this->svnCheckout();
     $awkCmd = '{print " --force \""$2"\""}';
@@ -539,7 +539,7 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function svnPublish() {
+  public function svnPublish() {
     $svn_dir = ".mp_svn";
     $plugin_version = $this->getPluginVersion('mailpoet.php');
     $plugin_dist_name = 'mailpoet';
@@ -825,13 +825,13 @@ class RoboFile extends \Robo\Tasks {
       ->run();
   }
 
-  function releaseChangelogGet($version = null) {
+  public function releaseChangelogGet($version = null) {
     $outputs = $this->getChangelogController()->get($version);
     $this->say("Changelog \n{$outputs[0]} \n{$outputs[1]}\n");
     $this->say("IMPORTANT NOTES \n" . ($outputs[2] ?: 'none'));
   }
 
-  function releaseChangelogWrite($version = null) {
+  public function releaseChangelogWrite($version = null) {
     $this->say("Updating changelog");
     $outputs = $this->getChangelogController()->update($version);
     $this->say("Changelog \n{$outputs[0]} \n{$outputs[1]}\n\n");
diff --git a/lib/API/API.php b/lib/API/API.php
index 74cf971041..abff538350 100644
--- a/lib/API/API.php
+++ b/lib/API/API.php
@@ -12,7 +12,7 @@ class API {
    * @return \MailPoet\API\MP\v1\API
    * @throws \Exception
    */
-  static function MP($version) {
+  public static function MP($version) {
     $api_class = sprintf('%s\MP\%s\API', __NAMESPACE__, $version);
     try {
       return ContainerWrapper::getInstance()->get($api_class);
diff --git a/lib/API/JSON/API.php b/lib/API/JSON/API.php
index 662c4d8ca8..fa52b69f2a 100644
--- a/lib/API/JSON/API.php
+++ b/lib/API/JSON/API.php
@@ -42,7 +42,7 @@ class API {
   const CURRENT_VERSION = 'v1';
 
 
-  function __construct(
+  public function __construct(
     ContainerInterface $container,
     AccessControl $access_control,
     SettingsController $settings,
@@ -60,7 +60,7 @@ class API {
     }
   }
 
-  function init() {
+  public function init() {
      // admin security token and API version
     WPFunctions::get()->addAction(
       'admin_head',
@@ -80,7 +80,7 @@ class API {
     );
   }
 
-  function setupAjax() {
+  public function setupAjax() {
     $this->wp->doAction('mailpoet_api_setup', [$this]);
 
     if (isset($_POST['api_version'])) {
@@ -105,7 +105,7 @@ class API {
     $response->send();
   }
 
-  function setRequestData($data, $request_type) {
+  public function setRequestData($data, $request_type) {
     $this->_request_api_version = !empty($data['api_version']) ? $data['api_version'] : false;
 
     $this->_request_endpoint = isset($data['endpoint'])
@@ -162,7 +162,7 @@ class API {
     }
   }
 
-  function processRoute() {
+  public function processRoute() {
     try {
       if (empty($this->_request_endpoint_class) ||
         !$this->container->has($this->_request_endpoint_class)
@@ -203,18 +203,18 @@ class API {
     }
   }
 
-  function validatePermissions($request_method, $permissions) {
+  public function validatePermissions($request_method, $permissions) {
     // validate method permission if defined, otherwise validate global permission
     return(!empty($permissions['methods'][$request_method])) ?
       $this->access_control->validatePermission($permissions['methods'][$request_method]) :
       $this->access_control->validatePermission($permissions['global']);
   }
 
-  function checkToken() {
+  public function checkToken() {
     return WPFunctions::get()->wpVerifyNonce($this->_request_token, 'mailpoet_token');
   }
 
-  function setTokenAndAPIVersion() {
+  public function setTokenAndAPIVersion() {
     $global = '<script type="text/javascript">';
     $global .= 'var mailpoet_token = "%s";';
     $global .= 'var mailpoet_api_version = "%s";';
@@ -226,24 +226,24 @@ class API {
     );
   }
 
-  function addEndpointNamespace($namespace, $version) {
+  public function addEndpointNamespace($namespace, $version) {
     if (!empty($this->_endpoint_namespaces[$version][$namespace])) return;
     $this->_endpoint_namespaces[$version][] = $namespace;
   }
 
-  function getEndpointNamespaces() {
+  public function getEndpointNamespaces() {
     return $this->_endpoint_namespaces;
   }
 
-  function getRequestedEndpointClass() {
+  public function getRequestedEndpointClass() {
     return $this->_request_endpoint_class;
   }
 
-  function getRequestedAPIVersion() {
+  public function getRequestedAPIVersion() {
     return $this->_request_api_version;
   }
 
-  function createErrorResponse($error_type, $error_message, $response_status) {
+  public function createErrorResponse($error_type, $error_message, $response_status) {
     $error_response = new ErrorResponse(
       [
         $error_type => $error_message,
diff --git a/lib/API/JSON/Endpoint.php b/lib/API/JSON/Endpoint.php
index 95c5ef987b..1f1a234eb6 100644
--- a/lib/API/JSON/Endpoint.php
+++ b/lib/API/JSON/Endpoint.php
@@ -16,13 +16,13 @@ abstract class Endpoint {
 
   protected static $get_methods = [];
 
-  function successResponse(
+  public function successResponse(
     $data = [], $meta = [], $status = Response::STATUS_OK
   ) {
     return new SuccessResponse($data, $meta, $status);
   }
 
-  function errorResponse(
+  public function errorResponse(
     $errors = [], $meta = [], $status = Response::STATUS_NOT_FOUND
   ) {
     if (empty($errors)) {
@@ -33,7 +33,7 @@ abstract class Endpoint {
     return new ErrorResponse($errors, $meta, $status);
   }
 
-  function badRequest($errors = [], $meta = []) {
+  public function badRequest($errors = [], $meta = []) {
     if (empty($errors)) {
       $errors = [
         Error::BAD_REQUEST => WPFunctions::get()->__('Invalid request parameters', 'mailpoet'),
diff --git a/lib/API/JSON/ErrorResponse.php b/lib/API/JSON/ErrorResponse.php
index 8c44c3e17e..50549a7188 100644
--- a/lib/API/JSON/ErrorResponse.php
+++ b/lib/API/JSON/ErrorResponse.php
@@ -7,16 +7,16 @@ use MailPoet\WP\Functions as WPFunctions;
 class ErrorResponse extends Response {
   public $errors;
 
-  function __construct($errors = [], $meta = [], $status = self::STATUS_NOT_FOUND) {
+  public function __construct($errors = [], $meta = [], $status = self::STATUS_NOT_FOUND) {
     parent::__construct($status, $meta);
     $this->errors = $this->formatErrors($errors);
   }
 
-  function getData() {
+  public function getData() {
     return (empty($this->errors)) ? null : ['errors' => $this->errors];
   }
 
-  function formatErrors($errors = []) {
+  public function formatErrors($errors = []) {
     return array_map(function($error, $message) {
       // sanitize SQL error
       if (preg_match('/^SQLSTATE/i', $message)) {
diff --git a/lib/API/JSON/Response.php b/lib/API/JSON/Response.php
index 8220c77e6b..8bb41da115 100644
--- a/lib/API/JSON/Response.php
+++ b/lib/API/JSON/Response.php
@@ -16,12 +16,12 @@ abstract class Response {
   public $status;
   public $meta;
 
-  function __construct($status, $meta = []) {
+  public function __construct($status, $meta = []) {
     $this->status = $status;
     $this->meta = $meta;
   }
 
-  function send() {
+  public function send() {
     WPFunctions::get()->statusHeader($this->status);
 
     $data = $this->getData();
@@ -41,5 +41,5 @@ abstract class Response {
     die();
   }
 
-  abstract function getData();
+  public abstract function getData();
 }
diff --git a/lib/API/JSON/ResponseBuilders/CustomFieldsResponseBuilder.php b/lib/API/JSON/ResponseBuilders/CustomFieldsResponseBuilder.php
index bb5526775b..6af75d5660 100644
--- a/lib/API/JSON/ResponseBuilders/CustomFieldsResponseBuilder.php
+++ b/lib/API/JSON/ResponseBuilders/CustomFieldsResponseBuilder.php
@@ -10,7 +10,7 @@ class CustomFieldsResponseBuilder {
    * @param CustomFieldEntity[] $custom_fields
    * @return array
    */
-  function buildBatch(array $custom_fields) {
+  public function buildBatch(array $custom_fields) {
     return array_map([$this, 'build'], $custom_fields);
   }
 
@@ -18,7 +18,7 @@ class CustomFieldsResponseBuilder {
    * @param CustomFieldEntity $custom_field
    * @return array
    */
-  function build(CustomFieldEntity $custom_field) {
+  public function build(CustomFieldEntity $custom_field) {
     return [
       'id' => $custom_field->getId(),
       'name' => $custom_field->getName(),
diff --git a/lib/API/JSON/ResponseBuilders/NewslettersResponseBuilder.php b/lib/API/JSON/ResponseBuilders/NewslettersResponseBuilder.php
index 831dd57582..148500fa90 100644
--- a/lib/API/JSON/ResponseBuilders/NewslettersResponseBuilder.php
+++ b/lib/API/JSON/ResponseBuilders/NewslettersResponseBuilder.php
@@ -9,7 +9,7 @@ use MailPoet\Entities\SendingQueueEntity;
 class NewslettersResponseBuilder {
   const DATE_FORMAT = 'Y-m-d H:i:s';
 
-  function build(NewsletterEntity $newsletter) {
+  public function build(NewsletterEntity $newsletter) {
     return [
       'id' => (string)$newsletter->getId(), // (string) for BC
       'hash' => $newsletter->getHash(),
diff --git a/lib/API/JSON/SuccessResponse.php b/lib/API/JSON/SuccessResponse.php
index f4c47e09f8..6720e3d5e0 100644
--- a/lib/API/JSON/SuccessResponse.php
+++ b/lib/API/JSON/SuccessResponse.php
@@ -5,12 +5,12 @@ namespace MailPoet\API\JSON;
 class SuccessResponse extends Response {
   public $data;
 
-  function __construct($data = [], $meta = [], $status = self::STATUS_OK) {
+  public function __construct($data = [], $meta = [], $status = self::STATUS_OK) {
     parent::__construct($status, $meta);
     $this->data = $data;
   }
 
-  function getData() {
+  public function getData() {
     if ($this->data === null) return null;
 
     return [
diff --git a/lib/API/JSON/v1/Analytics.php b/lib/API/JSON/v1/Analytics.php
index 45a5f279b1..0de8e24e87 100644
--- a/lib/API/JSON/v1/Analytics.php
+++ b/lib/API/JSON/v1/Analytics.php
@@ -15,11 +15,11 @@ class Analytics extends APIEndpoint {
     'global' => AccessControl::NO_ACCESS_RESTRICTION,
   ];
 
-  function __construct(Reporter $reporter) {
+  public function __construct(Reporter $reporter) {
     $this->reporter = $reporter;
   }
 
-  function getTrackingData() {
+  public function getTrackingData() {
       return $this->successResponse($this->reporter->getTrackingData());
   }
 }
diff --git a/lib/API/JSON/v1/AutomatedLatestContent.php b/lib/API/JSON/v1/AutomatedLatestContent.php
index ef3e855731..2196a0d35f 100644
--- a/lib/API/JSON/v1/AutomatedLatestContent.php
+++ b/lib/API/JSON/v1/AutomatedLatestContent.php
@@ -15,12 +15,12 @@ class AutomatedLatestContent extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_EMAILS,
   ];
 
-  function __construct(\MailPoet\Newsletter\AutomatedLatestContent $alc, WPFunctions $wp) {
+  public function __construct(\MailPoet\Newsletter\AutomatedLatestContent $alc, WPFunctions $wp) {
     $this->ALC = $alc;
     $this->wp = $wp;
   }
 
-  function getPostTypes() {
+  public function getPostTypes() {
     $post_types = array_map(function($post_type) {
       return [
         'name' => $post_type->name,
@@ -32,7 +32,7 @@ class AutomatedLatestContent extends APIEndpoint {
     );
   }
 
-  function getTaxonomies($data = []) {
+  public function getTaxonomies($data = []) {
     $post_type = (isset($data['postType'])) ? $data['postType'] : 'post';
     $all_taxonomies = WPFunctions::get()->getObjectTaxonomies($post_type, 'objects');
     $taxonomies_with_label = array_filter($all_taxonomies, function($taxonomy) {
@@ -41,7 +41,7 @@ class AutomatedLatestContent extends APIEndpoint {
     return $this->successResponse($taxonomies_with_label);
   }
 
-  function getTerms($data = []) {
+  public function getTerms($data = []) {
     $taxonomies = (isset($data['taxonomies'])) ? $data['taxonomies'] : [];
     $search = (isset($data['search'])) ? $data['search'] : '';
     $limit = (isset($data['limit'])) ? (int)$data['limit'] : 100;
@@ -62,20 +62,20 @@ class AutomatedLatestContent extends APIEndpoint {
     return $this->successResponse(array_values($terms));
   }
 
-  function getPosts($data = []) {
+  public function getPosts($data = []) {
     return $this->successResponse(
       $this->ALC->getPosts($data)
     );
   }
 
-  function getTransformedPosts($data = []) {
+  public function getTransformedPosts($data = []) {
     $posts = $this->ALC->getPosts($data);
     return $this->successResponse(
       $this->ALC->transformPosts($data, $posts)
     );
   }
 
-  function getBulkTransformedPosts($data = []) {
+  public function getBulkTransformedPosts($data = []) {
     $used_posts = [];
     $rendered_posts = [];
 
diff --git a/lib/API/JSON/v1/AutomaticEmails.php b/lib/API/JSON/v1/AutomaticEmails.php
index db3de47805..81bd6fb50e 100644
--- a/lib/API/JSON/v1/AutomaticEmails.php
+++ b/lib/API/JSON/v1/AutomaticEmails.php
@@ -14,11 +14,11 @@ class AutomaticEmails extends APIEndpoint {
 
   private $wp;
 
-  function __construct() {
+  public function __construct() {
     $this->wp = new WPFunctions;
   }
 
-  function getEventOptions($data) {
+  public function getEventOptions($data) {
     $query = (!empty($data['query'])) ? $data['query'] : null;
     $filter = (!empty($data['filter'])) ? $data['filter'] : null;
     $email_slug = (!empty($data['email_slug'])) ? $data['email_slug'] : null;
@@ -45,7 +45,7 @@ class AutomaticEmails extends APIEndpoint {
       );
   }
 
-  function getEventShortcodes($data) {
+  public function getEventShortcodes($data) {
     $email_slug = (!empty($data['email_slug'])) ? $data['email_slug'] : null;
     $event_slug = (!empty($data['event_slug'])) ? $data['event_slug'] : null;
 
diff --git a/lib/API/JSON/v1/CustomFields.php b/lib/API/JSON/v1/CustomFields.php
index 2c896c0191..cdf28be482 100644
--- a/lib/API/JSON/v1/CustomFields.php
+++ b/lib/API/JSON/v1/CustomFields.php
@@ -31,12 +31,12 @@ class CustomFields extends APIEndpoint {
     $this->custom_fields_response_builder = $custom_fields_response_builder;
   }
 
-  function getAll() {
+  public function getAll() {
     $collection = $this->custom_fields_repository->findBy([], ['created_at' => 'asc']);
     return $this->successResponse($this->custom_fields_response_builder->buildBatch($collection));
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : null);
     $custom_field = $this->custom_fields_repository->findOneById($id);
     if ($custom_field instanceof CustomFieldEntity) {
@@ -51,7 +51,7 @@ class CustomFields extends APIEndpoint {
     }
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     try {
       $custom_field = $this->custom_fields_repository->createOrUpdate($data);
       $custom_field = $this->custom_fields_repository->findOneById($custom_field->getId());
@@ -62,7 +62,7 @@ class CustomFields extends APIEndpoint {
     }
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : null);
     $custom_field = $this->custom_fields_repository->findOneById($id);
     if ($custom_field instanceof CustomFieldEntity) {
diff --git a/lib/API/JSON/v1/DynamicSegments.php b/lib/API/JSON/v1/DynamicSegments.php
index db6e0d0971..2f32ee0ea7 100644
--- a/lib/API/JSON/v1/DynamicSegments.php
+++ b/lib/API/JSON/v1/DynamicSegments.php
@@ -51,7 +51,7 @@ class DynamicSegments extends APIEndpoint {
     $this->subscribers_counts_loader = $subscribers_counts_loader ?: new SubscribersCount();
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     if (isset($data['id'])) {
       $id = (int)$data['id'];
     } else {
@@ -77,7 +77,7 @@ class DynamicSegments extends APIEndpoint {
     }
   }
 
-  function save($data) {
+  public function save($data) {
     try {
       $dynamic_segment = $this->mapper->mapDataToDB($data);
       $this->saver->save($dynamic_segment);
@@ -117,7 +117,7 @@ class DynamicSegments extends APIEndpoint {
     }
   }
 
-  function trash($data = []) {
+  public function trash($data = []) {
     if (isset($data['id'])) {
       $id = (int)$data['id'];
     } else {
@@ -140,7 +140,7 @@ class DynamicSegments extends APIEndpoint {
     }
   }
 
-  function restore($data = []) {
+  public function restore($data = []) {
     if (isset($data['id'])) {
       $id = (int)$data['id'];
     } else {
@@ -163,7 +163,7 @@ class DynamicSegments extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     if (isset($data['id'])) {
       $id = (int)$data['id'];
     } else {
@@ -183,7 +183,7 @@ class DynamicSegments extends APIEndpoint {
     }
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
     $listing_data = $this->listing_handler->get('\MailPoet\Models\DynamicSegment', $data);
 
     $data = [];
@@ -206,7 +206,7 @@ class DynamicSegments extends APIEndpoint {
 
   }
 
-  function bulkAction($data = []) {
+  public function bulkAction($data = []) {
     try {
       $meta = $this->bulk_action->apply('\MailPoet\Models\DynamicSegment', $data);
       return $this->successResponse(null, $meta);
diff --git a/lib/API/JSON/v1/FeatureFlags.php b/lib/API/JSON/v1/FeatureFlags.php
index ec7802660b..ffb638db87 100644
--- a/lib/API/JSON/v1/FeatureFlags.php
+++ b/lib/API/JSON/v1/FeatureFlags.php
@@ -20,17 +20,17 @@ class FeatureFlags extends APIEndpoint {
   /** @var FeatureFlagsController */
   private $feature_flags_controller;
 
-  function __construct(FeaturesController $features_controller, FeatureFlagsController $feature_flags) {
+  public function __construct(FeaturesController $features_controller, FeatureFlagsController $feature_flags) {
     $this->features_controller = $features_controller;
     $this->feature_flags_controller = $feature_flags;
   }
 
-  function getAll() {
+  public function getAll() {
     $feature_flags = $this->feature_flags_controller->getAll();
     return $this->successResponse($feature_flags);
   }
 
-  function set(array $flags) {
+  public function set(array $flags) {
     foreach ($flags as $name => $value) {
       if (!$this->features_controller->exists($name)) {
         return $this->badRequest([
diff --git a/lib/API/JSON/v1/Forms.php b/lib/API/JSON/v1/Forms.php
index 7aeee325af..8dc3cd9474 100644
--- a/lib/API/JSON/v1/Forms.php
+++ b/lib/API/JSON/v1/Forms.php
@@ -31,7 +31,7 @@ class Forms extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_FORMS,
   ];
 
-  function __construct(
+  public function __construct(
     Listing\BulkActionController $bulk_action,
     Listing\Handler $listing_handler,
     FeaturesController $features_controller,
@@ -43,7 +43,7 @@ class Forms extends APIEndpoint {
     $this->form_styles_utils = $form_styles_utils;
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
@@ -54,7 +54,7 @@ class Forms extends APIEndpoint {
     ]);
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
     $listing_data = $this->listing_handler->get('\MailPoet\Models\Form', $data);
 
     $data = [];
@@ -79,7 +79,7 @@ class Forms extends APIEndpoint {
     ]);
   }
 
-  function create() {
+  public function create() {
     $form_name = WPFunctions::get()->__('New form', 'mailpoet');
     if ($this->features_controller->isSupported(FeaturesController::NEW_FORM_EDITOR)) {
       $form_name = '';
@@ -123,7 +123,7 @@ class Forms extends APIEndpoint {
     return $this->save($form_data);
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     $form = Form::createOrUpdate($data);
     $errors = $form->getErrors();
 
@@ -135,7 +135,7 @@ class Forms extends APIEndpoint {
     return $this->badRequest($errors);
   }
 
-  function previewEditor($data = []) {
+  public function previewEditor($data = []) {
     // html
     $html = FormRenderer::renderHTML($data);
 
@@ -151,7 +151,7 @@ class Forms extends APIEndpoint {
     ]);
   }
 
-  function exportsEditor($data = []) {
+  public function exportsEditor($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
@@ -163,7 +163,7 @@ class Forms extends APIEndpoint {
     ]);
   }
 
-  function saveEditor($data = []) {
+  public function saveEditor($data = []) {
     $form_id = (isset($data['id']) ? (int)$data['id'] : 0);
     $name = (isset($data['name']) ? $data['name'] : WPFunctions::get()->__('New form', 'mailpoet'));
     $body = (isset($data['body']) ? $data['body'] : []);
@@ -232,7 +232,7 @@ class Forms extends APIEndpoint {
     );
   }
 
-  function restore($data = []) {
+  public function restore($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
@@ -250,7 +250,7 @@ class Forms extends APIEndpoint {
     }
   }
 
-  function trash($data = []) {
+  public function trash($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
@@ -268,7 +268,7 @@ class Forms extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
@@ -282,7 +282,7 @@ class Forms extends APIEndpoint {
     }
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $form = Form::findOne($id);
 
@@ -311,7 +311,7 @@ class Forms extends APIEndpoint {
     }
   }
 
-  function bulkAction($data = []) {
+  public function bulkAction($data = []) {
     try {
       $meta = $this->bulk_action->apply('\MailPoet\Models\Form', $data);
       return $this->successResponse(null, $meta);
diff --git a/lib/API/JSON/v1/ImportExport.php b/lib/API/JSON/v1/ImportExport.php
index 41ec4b4d26..e0f23c4ce3 100644
--- a/lib/API/JSON/v1/ImportExport.php
+++ b/lib/API/JSON/v1/ImportExport.php
@@ -15,7 +15,7 @@ class ImportExport extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_SUBSCRIBERS,
   ];
 
-  function getMailChimpLists($data) {
+  public function getMailChimpLists($data) {
     try {
       $mailChimp = new MailChimp($data['api_key']);
       $lists = $mailChimp->getLists();
@@ -27,7 +27,7 @@ class ImportExport extends APIEndpoint {
     }
   }
 
-  function getMailChimpSubscribers($data) {
+  public function getMailChimpSubscribers($data) {
     try {
       $mailChimp = new MailChimp($data['api_key']);
       $subscribers = $mailChimp->getSubscribers($data['lists']);
@@ -39,7 +39,7 @@ class ImportExport extends APIEndpoint {
     }
   }
 
-  function addSegment($data) {
+  public function addSegment($data) {
     $segment = Segment::createOrUpdate($data);
     $errors = $segment->getErrors();
 
@@ -52,7 +52,7 @@ class ImportExport extends APIEndpoint {
     }
   }
 
-  function processImport($data) {
+  public function processImport($data) {
     try {
       $import = new \MailPoet\Subscribers\ImportExport\Import\Import(
         json_decode($data, true)
@@ -66,7 +66,7 @@ class ImportExport extends APIEndpoint {
     }
   }
 
-  function processExport($data) {
+  public function processExport($data) {
     try {
       $export = new \MailPoet\Subscribers\ImportExport\Export\Export(
         json_decode($data, true)
@@ -80,7 +80,7 @@ class ImportExport extends APIEndpoint {
     }
   }
 
-  function setupWooCommerceInitialImport() {
+  public function setupWooCommerceInitialImport() {
     try {
       $task = ScheduledTask::where('type', WooCommerceSync::TASK_TYPE)
         ->whereRaw('status = ? OR status IS NULL', [ScheduledTask::STATUS_SCHEDULED])
diff --git a/lib/API/JSON/v1/Mailer.php b/lib/API/JSON/v1/Mailer.php
index 238588a1a2..2a97185c8b 100644
--- a/lib/API/JSON/v1/Mailer.php
+++ b/lib/API/JSON/v1/Mailer.php
@@ -30,14 +30,14 @@ class Mailer extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_EMAILS,
   ];
 
-  function __construct(AuthorizedEmailsController $authorized_emails_controller, SettingsController $settings, Bridge $bridge, MetaInfo $mailerMetaInfo) {
+  public function __construct(AuthorizedEmailsController $authorized_emails_controller, SettingsController $settings, Bridge $bridge, MetaInfo $mailerMetaInfo) {
     $this->authorized_emails_controller = $authorized_emails_controller;
     $this->settings = $settings;
     $this->bridge = $bridge;
     $this->mailerMetaInfo = $mailerMetaInfo;
   }
 
-  function send($data = []) {
+  public function send($data = []) {
     try {
       $mailer = new \MailPoet\Mailer\Mailer();
       $mailer->init(
@@ -67,7 +67,7 @@ class Mailer extends APIEndpoint {
     }
   }
 
-  function resumeSending() {
+  public function resumeSending() {
     if ($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING)) {
       $this->authorized_emails_controller->checkAuthorizedEmailAddresses();
     }
@@ -75,7 +75,7 @@ class Mailer extends APIEndpoint {
     return $this->successResponse(null);
   }
 
-  function getAuthorizedEmailAddresses() {
+  public function getAuthorizedEmailAddresses() {
     $authorized_emails = $this->bridge->getAuthorizedEmailAddresses();
     return $this->successResponse($authorized_emails);
   }
diff --git a/lib/API/JSON/v1/NewsletterLinks.php b/lib/API/JSON/v1/NewsletterLinks.php
index 5f359db6f9..4c3676ba16 100644
--- a/lib/API/JSON/v1/NewsletterLinks.php
+++ b/lib/API/JSON/v1/NewsletterLinks.php
@@ -12,7 +12,7 @@ class NewsletterLinks extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_SEGMENTS,
   ];
 
-  function get($data = []) {
+  public function get($data = []) {
     $links = NewsletterLink::select(['id', 'url'])->where('newsletter_id', $data['newsletterId'])->findArray();
     return $this->successResponse($links);
   }
diff --git a/lib/API/JSON/v1/NewsletterTemplates.php b/lib/API/JSON/v1/NewsletterTemplates.php
index 5822791d87..1feb5879ec 100644
--- a/lib/API/JSON/v1/NewsletterTemplates.php
+++ b/lib/API/JSON/v1/NewsletterTemplates.php
@@ -17,7 +17,7 @@ class NewsletterTemplates extends APIEndpoint {
     'getAll',
   ];
 
-  function get($data = []) {
+  public function get($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $template = NewsletterTemplate::findOne($id);
     if ($template instanceof NewsletterTemplate) {
@@ -31,7 +31,7 @@ class NewsletterTemplates extends APIEndpoint {
     }
   }
 
-  function getAll() {
+  public function getAll() {
     $collection = NewsletterTemplate
       ::selectExpr('id, categories, thumbnail, name, description, readonly')
       ->orderByAsc('readonly')
@@ -45,7 +45,7 @@ class NewsletterTemplates extends APIEndpoint {
     return $this->successResponse($templates);
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     ignore_user_abort(true);
     if (!empty($data['newsletter_id'])) {
       $template = NewsletterTemplate::whereEqual('newsletter_id', $data['newsletter_id'])->findOne();
@@ -70,7 +70,7 @@ class NewsletterTemplates extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $template = NewsletterTemplate::findOne($id);
     if ($template instanceof NewsletterTemplate) {
diff --git a/lib/API/JSON/v1/Newsletters.php b/lib/API/JSON/v1/Newsletters.php
index 6dff2329c0..695bcf4600 100644
--- a/lib/API/JSON/v1/Newsletters.php
+++ b/lib/API/JSON/v1/Newsletters.php
@@ -80,7 +80,7 @@ class Newsletters extends APIEndpoint {
   /** @var SubscribersFeature */
   private $subscribers_feature;
 
-  function __construct(
+  public function __construct(
     Listing\BulkActionController $bulk_action,
     Listing\Handler $listing_handler,
     WPFunctions $wp,
@@ -112,7 +112,7 @@ class Newsletters extends APIEndpoint {
     $this->subscribers_feature = $subscribers_feature;
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     $newsletter = isset($data['id'])
       ? $this->newsletters_repository->findOneById((int)$data['id'])
       : null;
@@ -137,7 +137,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function getWithStats($data = []) {
+  public function getWithStats($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $newsletter = Newsletter::findOne($id);
     if ($newsletter instanceof Newsletter) {
@@ -164,7 +164,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     $data = $this->wp->applyFilters('mailpoet_api_newsletters_save_before', $data);
 
     $segments = [];
@@ -286,7 +286,7 @@ class Newsletters extends APIEndpoint {
     return $this->successResponse($newsletter->asArray(), ['preview_url' => $preview_url]);
   }
 
-  function setStatus($data = []) {
+  public function setStatus($data = []) {
     $status = (isset($data['status']) ? $data['status'] : null);
 
     if (!$status) {
@@ -339,7 +339,7 @@ class Newsletters extends APIEndpoint {
     );
   }
 
-  function restore($data = []) {
+  public function restore($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $newsletter = Newsletter::findOne($id);
     if ($newsletter instanceof Newsletter) {
@@ -359,7 +359,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function trash($data = []) {
+  public function trash($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $newsletter = Newsletter::findOne($id);
     if ($newsletter instanceof Newsletter) {
@@ -378,7 +378,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $newsletter = Newsletter::findOne($id);
     if ($newsletter instanceof Newsletter) {
@@ -391,7 +391,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $newsletter = Newsletter::findOne($id);
 
@@ -420,7 +420,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function showPreview($data = []) {
+  public function showPreview($data = []) {
     if (empty($data['body'])) {
       return $this->badRequest([
         APIError::BAD_REQUEST => __('Newsletter data is missing.', 'mailpoet'),
@@ -456,7 +456,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function sendPreview($data = []) {
+  public function sendPreview($data = []) {
     if (empty($data['subscriber'])) {
       return $this->badRequest([
         APIError::BAD_REQUEST => __('Please specify receiver information.', 'mailpoet'),
@@ -527,7 +527,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
     $listing_data = $this->listing_handler->get('\MailPoet\Models\Newsletter', $data);
 
     $data = [];
@@ -585,7 +585,7 @@ class Newsletters extends APIEndpoint {
     ]);
   }
 
-  function bulkAction($data = []) {
+  public function bulkAction($data = []) {
     try {
       $meta = $this->bulk_action->apply('\MailPoet\Models\Newsletter', $data);
       return $this->successResponse(null, $meta);
@@ -596,7 +596,7 @@ class Newsletters extends APIEndpoint {
     }
   }
 
-  function create($data = []) {
+  public function create($data = []) {
     $options = [];
     if (isset($data['options'])) {
       $options = $data['options'];
diff --git a/lib/API/JSON/v1/Segments.php b/lib/API/JSON/v1/Segments.php
index 43b06765f6..7a3457143b 100644
--- a/lib/API/JSON/v1/Segments.php
+++ b/lib/API/JSON/v1/Segments.php
@@ -25,7 +25,7 @@ class Segments extends APIEndpoint {
   /** @var WooCommerce */
   private $woo_commerce_sync;
 
-  function __construct(
+  public function __construct(
     Listing\BulkActionController $bulk_action,
     Listing\Handler $listing_handler,
     WooCommerce $woo_commerce
@@ -35,7 +35,7 @@ class Segments extends APIEndpoint {
     $this->woo_commerce_sync = $woo_commerce;
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $segment = Segment::findOne($id);
     if ($segment instanceof Segment) {
@@ -47,7 +47,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
     $listing_data = $this->listing_handler->get('\MailPoet\Models\Segment', $data);
 
     $data = [];
@@ -69,7 +69,7 @@ class Segments extends APIEndpoint {
     ]);
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     $segment = Segment::createOrUpdate($data);
     $errors = $segment->getErrors();
 
@@ -84,7 +84,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function restore($data = []) {
+  public function restore($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $segment = Segment::findOne($id);
     if ($segment instanceof Segment) {
@@ -102,7 +102,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function trash($data = []) {
+  public function trash($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $segment = Segment::findOne($id);
     if ($segment instanceof Segment) {
@@ -120,7 +120,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $segment = Segment::findOne($id);
     if ($segment instanceof Segment) {
@@ -133,7 +133,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $segment = Segment::findOne($id);
 
@@ -161,7 +161,7 @@ class Segments extends APIEndpoint {
     }
   }
 
-  function synchronize($data) {
+  public function synchronize($data) {
     try {
       if ($data['type'] === Segment::TYPE_WC_USERS) {
         $this->woo_commerce_sync->synchronizeCustomers();
@@ -177,7 +177,7 @@ class Segments extends APIEndpoint {
     return $this->successResponse(null);
   }
 
-  function bulkAction($data = []) {
+  public function bulkAction($data = []) {
     try {
       $meta = $this->bulk_action->apply('\MailPoet\Models\Segment', $data);
       return $this->successResponse(null, $meta);
diff --git a/lib/API/JSON/v1/SendingQueue.php b/lib/API/JSON/v1/SendingQueue.php
index e8bb8bb53d..1ba7bfc81c 100644
--- a/lib/API/JSON/v1/SendingQueue.php
+++ b/lib/API/JSON/v1/SendingQueue.php
@@ -23,11 +23,11 @@ class SendingQueue extends APIEndpoint {
   /** @var SubscribersFeature */
   private $subscribers_feature;
 
-  function __construct(SubscribersFeature $subscribers_feature) {
+  public function __construct(SubscribersFeature $subscribers_feature) {
     $this->subscribers_feature = $subscribers_feature;
   }
 
-  function add($data = []) {
+  public function add($data = []) {
     if ($this->subscribers_feature->check()) {
       return $this->errorResponse([
         APIError::FORBIDDEN => __('Subscribers limit reached.', 'mailpoet'),
@@ -117,7 +117,7 @@ class SendingQueue extends APIEndpoint {
     }
   }
 
-  function pause($data = []) {
+  public function pause($data = []) {
     $newsletter_id = (isset($data['newsletter_id'])
       ? (int)$data['newsletter_id']
       : false
@@ -144,7 +144,7 @@ class SendingQueue extends APIEndpoint {
     }
   }
 
-  function resume($data = []) {
+  public function resume($data = []) {
     if ($this->subscribers_feature->check()) {
       return $this->errorResponse([
         APIError::FORBIDDEN => __('Subscribers limit reached.', 'mailpoet'),
diff --git a/lib/API/JSON/v1/SendingTaskSubscribers.php b/lib/API/JSON/v1/SendingTaskSubscribers.php
index a942899bdf..885a2d7f74 100644
--- a/lib/API/JSON/v1/SendingTaskSubscribers.php
+++ b/lib/API/JSON/v1/SendingTaskSubscribers.php
@@ -31,7 +31,7 @@ class SendingTaskSubscribers extends APIEndpoint {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(
+  public function __construct(
     Listing\Handler $listing_handler,
     SettingsController $settings,
     CronHelper $cron_helper,
@@ -43,7 +43,7 @@ class SendingTaskSubscribers extends APIEndpoint {
     $this->wp = $wp;
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
     $newsletter_id = !empty($data['params']['id']) ? (int)$data['params']['id'] : false;
     $tasks_ids = SendingQueueModel::select('task_id')
       ->where('newsletter_id', $newsletter_id)
@@ -72,7 +72,7 @@ class SendingTaskSubscribers extends APIEndpoint {
     ]);
   }
 
-  function resend($data = []) {
+  public function resend($data = []) {
     $task_id = !empty($data['taskId']) ? (int)$data['taskId'] : false;
     $subscriber_id = !empty($data['subscriberId']) ? (int)$data['subscriberId'] : false;
     $task_subscriber = ScheduledTaskSubscriber::where('task_id', $task_id)
diff --git a/lib/API/JSON/v1/Services.php b/lib/API/JSON/v1/Services.php
index 2c381eef77..176742c5d6 100644
--- a/lib/API/JSON/v1/Services.php
+++ b/lib/API/JSON/v1/Services.php
@@ -33,7 +33,7 @@ class Services extends APIEndpoint {
     'global' => AccessControl::PERMISSION_MANAGE_SETTINGS,
   ];
 
-  function __construct(Bridge $bridge, SettingsController $settings, AnalyticsHelper $analytics, SPFCheck $spf_check) {
+  public function __construct(Bridge $bridge, SettingsController $settings, AnalyticsHelper $analytics, SPFCheck $spf_check) {
     $this->bridge = $bridge;
     $this->settings = $settings;
     $this->analytics = $analytics;
@@ -41,7 +41,7 @@ class Services extends APIEndpoint {
     $this->date_time = new DateTime();
   }
 
-  function checkSPFRecord($data = []) {
+  public function checkSPFRecord($data = []) {
     $sender_address = $this->settings->get('sender.address');
     $domain_name = mb_substr($sender_address, mb_strpos($sender_address, '@') + 1);
 
@@ -57,7 +57,7 @@ class Services extends APIEndpoint {
     return $this->successResponse();
   }
 
-  function checkMSSKey($data = []) {
+  public function checkMSSKey($data = []) {
     $key = isset($data['key']) ? trim($data['key']) : null;
 
     if (!$key) {
@@ -119,7 +119,7 @@ class Services extends APIEndpoint {
     return $this->errorResponse([APIError::BAD_REQUEST => $error]);
   }
 
-  function checkPremiumKey($data = []) {
+  public function checkPremiumKey($data = []) {
     $key = isset($data['key']) ? trim($data['key']) : null;
 
     if (!$key) {
diff --git a/lib/API/JSON/v1/Settings.php b/lib/API/JSON/v1/Settings.php
index 2efa9e860c..489090dfe8 100644
--- a/lib/API/JSON/v1/Settings.php
+++ b/lib/API/JSON/v1/Settings.php
@@ -47,11 +47,11 @@ class Settings extends APIEndpoint {
     $this->wc_transactional_emails = $wc_transactional_emails;
   }
 
-  function get() {
+  public function get() {
     return $this->successResponse($this->settings->getAll());
   }
 
-  function set($settings = []) {
+  public function set($settings = []) {
     if (empty($settings)) {
       return $this->badRequest(
         [
diff --git a/lib/API/JSON/v1/Setup.php b/lib/API/JSON/v1/Setup.php
index e4dd6ca731..4ce6b4d190 100644
--- a/lib/API/JSON/v1/Setup.php
+++ b/lib/API/JSON/v1/Setup.php
@@ -18,12 +18,12 @@ class Setup extends APIEndpoint {
   /** @var Activator */
   private $activator;
 
-  function __construct(WPFunctions $wp, Activator $activator) {
+  public function __construct(WPFunctions $wp, Activator $activator) {
     $this->wp = $wp;
     $this->activator = $activator;
   }
 
-  function reset() {
+  public function reset() {
     try {
       $this->activator->deactivate();
       $this->activator->activate();
diff --git a/lib/API/JSON/v1/Subscribers.php b/lib/API/JSON/v1/Subscribers.php
index e6c8ee45c1..554e57d297 100644
--- a/lib/API/JSON/v1/Subscribers.php
+++ b/lib/API/JSON/v1/Subscribers.php
@@ -94,7 +94,7 @@ class Subscribers extends APIEndpoint {
     $this->subscription_url_factory = $subscription_url_factory;
   }
 
-  function get($data = []) {
+  public function get($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $subscriber = Subscriber::findOne($id);
     if ($subscriber === false) {
@@ -111,7 +111,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function listing($data = []) {
+  public function listing($data = []) {
 
     if (!isset($data['filter']['segment'])) {
       $listing_data = $this->listing_handler->get('\MailPoet\Models\Subscriber', $data);
@@ -159,7 +159,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function subscribe($data = []) {
+  public function subscribe($data = []) {
     $form_id = (isset($data['form_id']) ? (int)$data['form_id'] : false);
     $form = Form::findOne($form_id);
     unset($data['form_id']);
@@ -336,7 +336,7 @@ class Subscribers extends APIEndpoint {
     return true;
   }
 
-  function save($data = []) {
+  public function save($data = []) {
     if (empty($data['segments'])) {
       $data['segments'] = [];
     }
@@ -400,7 +400,7 @@ class Subscribers extends APIEndpoint {
     return array_diff($data['segments'], $old_segment_ids);
   }
 
-  function restore($data = []) {
+  public function restore($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $subscriber = Subscriber::findOne($id);
     if ($subscriber instanceof Subscriber) {
@@ -418,7 +418,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function trash($data = []) {
+  public function trash($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $subscriber = Subscriber::findOne($id);
     if ($subscriber instanceof Subscriber) {
@@ -436,7 +436,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function delete($data = []) {
+  public function delete($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $subscriber = Subscriber::findOne($id);
     if ($subscriber instanceof Subscriber) {
@@ -449,7 +449,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function sendConfirmationEmail($data = []) {
+  public function sendConfirmationEmail($data = []) {
     $id = (isset($data['id']) ? (int)$data['id'] : false);
     $subscriber = Subscriber::findOne($id);
     if ($subscriber instanceof Subscriber) {
@@ -464,7 +464,7 @@ class Subscribers extends APIEndpoint {
     }
   }
 
-  function bulkAction($data = []) {
+  public function bulkAction($data = []) {
     try {
       if (!isset($data['listing']['filter']['segment'])) {
         return $this->successResponse(
diff --git a/lib/API/JSON/v1/UserFlags.php b/lib/API/JSON/v1/UserFlags.php
index 5c32c9e9ee..23b72051ee 100644
--- a/lib/API/JSON/v1/UserFlags.php
+++ b/lib/API/JSON/v1/UserFlags.php
@@ -17,11 +17,11 @@ class UserFlags extends APIEndpoint {
     'global' => AccessControl::ALL_ROLES_ACCESS,
   ];
 
-  function __construct(UserFlagsController $user_flags) {
+  public function __construct(UserFlagsController $user_flags) {
     $this->user_flags = $user_flags;
   }
 
-  function set(array $flags = []) {
+  public function set(array $flags = []) {
     if (empty($flags)) {
       return $this->badRequest(
         [
diff --git a/lib/API/JSON/v1/WoocommerceSettings.php b/lib/API/JSON/v1/WoocommerceSettings.php
index 6b433d940c..bff011443d 100644
--- a/lib/API/JSON/v1/WoocommerceSettings.php
+++ b/lib/API/JSON/v1/WoocommerceSettings.php
@@ -18,11 +18,11 @@ class WoocommerceSettings extends APIEndpoint {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function set($data = []) {
+  public function set($data = []) {
     foreach ($data as $option => $value) {
       if (in_array($option, $this->allowed_settings)) {
         $this->wp->updateOption($option, $value);
diff --git a/lib/API/MP/v1/API.php b/lib/API/MP/v1/API.php
index af991f0a64..209f78afb9 100644
--- a/lib/API/MP/v1/API.php
+++ b/lib/API/MP/v1/API.php
@@ -47,7 +47,7 @@ class API {
     $this->welcome_scheduler = $welcome_scheduler;
   }
 
-  function getSubscriberFields() {
+  public function getSubscriberFields() {
     $data = [
       [
         'id' => 'email',
@@ -93,7 +93,7 @@ class API {
     return $data;
   }
 
-  function addSubscriberField(array $data = []) {
+  public function addSubscriberField(array $data = []) {
     try {
       $custom_field = CustomField::createOrUpdate($this->custom_fields_data_sanitizer->sanitize($data));
       $errors = $custom_field->getErrors();
@@ -110,11 +110,11 @@ class API {
     }
   }
 
-  function subscribeToList($subscriber_id, $list_id, $options = []) {
+  public function subscribeToList($subscriber_id, $list_id, $options = []) {
     return $this->subscribeToLists($subscriber_id, [$list_id], $options);
   }
 
-  function subscribeToLists($subscriber_id, array $list_ids, $options = []) {
+  public function subscribeToLists($subscriber_id, array $list_ids, $options = []) {
     $schedule_welcome_email = (isset($options['schedule_welcome_email']) && $options['schedule_welcome_email'] === false) ? false : true;
     $send_confirmation_email = (isset($options['send_confirmation_email']) && $options['send_confirmation_email'] === false) ? false : true;
     $skip_subscriber_notification = (isset($options['skip_subscriber_notification']) && $options['skip_subscriber_notification'] === true) ? true : false;
@@ -189,11 +189,11 @@ class API {
     return $subscriber->withCustomFields()->withSubscriptions()->asArray();
   }
 
-  function unsubscribeFromList($subscriber_id, $list_id) {
+  public function unsubscribeFromList($subscriber_id, $list_id) {
     return $this->unsubscribeFromLists($subscriber_id, [$list_id]);
   }
 
-  function unsubscribeFromLists($subscriber_id, array $list_ids) {
+  public function unsubscribeFromLists($subscriber_id, array $list_ids) {
     if (empty($list_ids)) {
       throw new APIException(__('At least one segment ID is required.', 'mailpoet'), APIException::SEGMENT_REQUIRED);
     }
@@ -237,12 +237,12 @@ class API {
     return $subscriber->withCustomFields()->withSubscriptions()->asArray();
   }
 
-  function getLists() {
+  public function getLists() {
     return Segment::where('type', Segment::TYPE_DEFAULT)
       ->findArray();
   }
 
-  function addSubscriber(array $subscriber, $list_ids = [], $options = []) {
+  public function addSubscriber(array $subscriber, $list_ids = [], $options = []) {
     $send_confirmation_email = (isset($options['send_confirmation_email']) && $options['send_confirmation_email'] === false) ? false : true;
     $schedule_welcome_email = (isset($options['schedule_welcome_email']) && $options['schedule_welcome_email'] === false) ? false : true;
     $skip_subscriber_notification = (isset($options['skip_subscriber_notification']) && $options['skip_subscriber_notification'] === true) ? true : false;
@@ -316,7 +316,7 @@ class API {
     return $new_subscriber->withCustomFields()->withSubscriptions()->asArray();
   }
 
-  function addList(array $list) {
+  public function addList(array $list) {
     // throw exception when list name is missing
     if (empty($list['name'])) {
       throw new APIException(
@@ -356,7 +356,7 @@ class API {
     return $new_list->asArray();
   }
 
-  function getSubscriber($subscriber_email) {
+  public function getSubscriber($subscriber_email) {
     $subscriber = Subscriber::findOne($subscriber_email);
     // throw exception when subscriber does not exist
     if (!$subscriber) {
diff --git a/lib/AdminPages/PageRenderer.php b/lib/AdminPages/PageRenderer.php
index 8eccd96c1b..b636050fb5 100644
--- a/lib/AdminPages/PageRenderer.php
+++ b/lib/AdminPages/PageRenderer.php
@@ -20,7 +20,7 @@ class PageRenderer {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(
+  public function __construct(
     Renderer $renderer,
     FeaturesController $features_controller,
     SettingsController $settings
@@ -35,7 +35,7 @@ class PageRenderer {
    * @param string $template
    * @param array $data
    */
-  function displayPage($template, array $data = []) {
+  public function displayPage($template, array $data = []) {
     $defaults = [
       'feature_flags' => $this->features_controller->getAllFlags(),
       'referral_id' => $this->settings->get(ReferralDetector::REFERRAL_SETTING_NAME),
diff --git a/lib/AdminPages/Pages/DynamicSegments.php b/lib/AdminPages/Pages/DynamicSegments.php
index ddeea118e0..65bab99ede 100644
--- a/lib/AdminPages/Pages/DynamicSegments.php
+++ b/lib/AdminPages/Pages/DynamicSegments.php
@@ -21,7 +21,7 @@ class DynamicSegments {
   /** @var WooCommerceHelper */
   private $woocommerce_helper;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     PageLimit $listing_page_limit,
     WPFunctions $wp,
@@ -33,7 +33,7 @@ class DynamicSegments {
     $this->woocommerce_helper = $woocommerce_helper;
   }
 
-  function render() {
+  public function render() {
     $data = [];
     $data['items_per_page'] = $this->listing_page_limit->getLimitPerPage('dynamic_segments');
 
diff --git a/lib/AdminPages/Pages/ExperimentalFeatures.php b/lib/AdminPages/Pages/ExperimentalFeatures.php
index ac70d6a105..be10a72c79 100644
--- a/lib/AdminPages/Pages/ExperimentalFeatures.php
+++ b/lib/AdminPages/Pages/ExperimentalFeatures.php
@@ -8,11 +8,11 @@ class ExperimentalFeatures {
   /** @var PageRenderer */
   private $page_renderer;
 
-  function __construct(PageRenderer $page_renderer) {
+  public function __construct(PageRenderer $page_renderer) {
     $this->page_renderer = $page_renderer;
   }
 
-  function render() {
+  public function render() {
     $this->page_renderer->displayPage('experimental-features.html', []);
   }
 }
diff --git a/lib/AdminPages/Pages/FormEditor.php b/lib/AdminPages/Pages/FormEditor.php
index 3a3284058e..f82cb90cbd 100644
--- a/lib/AdminPages/Pages/FormEditor.php
+++ b/lib/AdminPages/Pages/FormEditor.php
@@ -27,7 +27,7 @@ class FormEditor {
   /** @var CustomFieldsResponseBuilder */
   private $custom_fields_response_builder;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     FeaturesController $features_controller,
     CustomFieldsRepository $custom_fields_repository,
@@ -39,7 +39,7 @@ class FormEditor {
     $this->custom_fields_response_builder = $custom_fields_response_builder;
   }
 
-  function render() {
+  public function render() {
     $id = (isset($_GET['id']) ? (int)$_GET['id'] : 0);
     $form = Form::findOne($id);
     if ($form instanceof Form) {
diff --git a/lib/AdminPages/Pages/Forms.php b/lib/AdminPages/Pages/Forms.php
index 787a7433fe..b63426c3d4 100644
--- a/lib/AdminPages/Pages/Forms.php
+++ b/lib/AdminPages/Pages/Forms.php
@@ -17,7 +17,7 @@ class Forms {
   /** @var Installation */
   private $installation;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     PageLimit $listing_page_limit,
     Installation $installation
@@ -27,7 +27,7 @@ class Forms {
     $this->installation = $installation;
   }
 
-  function render() {
+  public function render() {
     $data = [];
     $data['items_per_page'] = $this->listing_page_limit->getLimitPerPage('forms');
     $data['segments'] = Segment::findArray();
diff --git a/lib/AdminPages/Pages/Help.php b/lib/AdminPages/Pages/Help.php
index cdf8a7ebe4..bee5f2fab6 100644
--- a/lib/AdminPages/Pages/Help.php
+++ b/lib/AdminPages/Pages/Help.php
@@ -24,14 +24,14 @@ class Help {
   /** @var Beacon */
   private $helpscout_beacon;
 
-  function __construct(PageRenderer $page_renderer, State $tasks_state, CronHelper $cron_helper, Beacon $helpscout_beacon) {
+  public function __construct(PageRenderer $page_renderer, State $tasks_state, CronHelper $cron_helper, Beacon $helpscout_beacon) {
     $this->page_renderer = $page_renderer;
     $this->tasks_state = $tasks_state;
     $this->cron_helper = $cron_helper;
     $this->helpscout_beacon = $helpscout_beacon;
   }
 
-  function render() {
+  public function render() {
     $system_info_data = $this->helpscout_beacon->getData();
     $cron_ping_response = $this->cron_helper->pingDaemon();
     $system_status_data = [
diff --git a/lib/AdminPages/Pages/MP2Migration.php b/lib/AdminPages/Pages/MP2Migration.php
index 788311ab3e..be84076bf0 100644
--- a/lib/AdminPages/Pages/MP2Migration.php
+++ b/lib/AdminPages/Pages/MP2Migration.php
@@ -12,12 +12,12 @@ class MP2Migration {
   /** @var MP2Migrator */
   private $mp2_migrator;
 
-  function __construct(PageRenderer $page_renderer, MP2Migrator $mp2_migrator) {
+  public function __construct(PageRenderer $page_renderer, MP2Migrator $mp2_migrator) {
     $this->page_renderer = $page_renderer;
     $this->mp2_migrator = $mp2_migrator;
   }
 
-  function render() {
+  public function render() {
     $this->mp2_migrator->init();
     $data = [
       'log_file_url' => $this->mp2_migrator->log_file_url,
diff --git a/lib/AdminPages/Pages/NewsletterEditor.php b/lib/AdminPages/Pages/NewsletterEditor.php
index 40529d4093..681f468121 100644
--- a/lib/AdminPages/Pages/NewsletterEditor.php
+++ b/lib/AdminPages/Pages/NewsletterEditor.php
@@ -32,7 +32,7 @@ class NewsletterEditor {
   /** @var TransactionalEmails */
   private $wc_transactional_emails;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     SettingsController $settings,
     UserFlagsController $user_flags,
@@ -48,7 +48,7 @@ class NewsletterEditor {
     $this->wc_transactional_emails = $wc_transactional_emails;
   }
 
-  function render() {
+  public function render() {
     $newsletter_id = (isset($_GET['id']) ? (int)$_GET['id'] : 0);
     $woocommerce_template_id = (int)$this->settings->get(TransactionalEmails::SETTING_EMAIL_ID, null);
     if (
diff --git a/lib/AdminPages/Pages/Newsletters.php b/lib/AdminPages/Pages/Newsletters.php
index 7b83d14282..5d812f4a74 100644
--- a/lib/AdminPages/Pages/Newsletters.php
+++ b/lib/AdminPages/Pages/Newsletters.php
@@ -50,7 +50,7 @@ class Newsletters {
   /** @var SubscribersFeature */
   private $subscribers_feature;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     PageLimit $listing_page_limit,
     WPFunctions $wp,
@@ -72,7 +72,7 @@ class Newsletters {
     $this->subscribers_feature = $subscribers_feature;
   }
 
-  function render() {
+  public function render() {
     global $wp_roles;
 
     $data = [];
diff --git a/lib/AdminPages/Pages/Premium.php b/lib/AdminPages/Pages/Premium.php
index f7e69aa4f4..ec2ebc88d1 100644
--- a/lib/AdminPages/Pages/Premium.php
+++ b/lib/AdminPages/Pages/Premium.php
@@ -13,12 +13,12 @@ class Premium {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
+  public function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
     $this->page_renderer = $page_renderer;
     $this->wp = $wp;
   }
 
-  function render() {
+  public function render() {
     $data = [
       'current_wp_user' => $this->wp->wpGetCurrentUser()->to_array(),
       'subscriber_count' => Subscriber::getTotalSubscribers(),
diff --git a/lib/AdminPages/Pages/RevenueTrackingPermission.php b/lib/AdminPages/Pages/RevenueTrackingPermission.php
index b8bf3f9a92..3dad550eec 100644
--- a/lib/AdminPages/Pages/RevenueTrackingPermission.php
+++ b/lib/AdminPages/Pages/RevenueTrackingPermission.php
@@ -13,7 +13,7 @@ class RevenueTrackingPermission {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     WPFunctions $wp
   ) {
@@ -21,7 +21,7 @@ class RevenueTrackingPermission {
     $this->wp = $wp;
   }
 
-  function render() {
+  public function render() {
     if ((bool)(defined('DOING_AJAX') && DOING_AJAX)) return;
     $data = [
       'finish_wizard_url' => $this->wp->adminUrl('admin.php?page=' . Menu::MAIN_PAGE_SLUG),
diff --git a/lib/AdminPages/Pages/Segments.php b/lib/AdminPages/Pages/Segments.php
index 99a04c6455..7813a9d437 100644
--- a/lib/AdminPages/Pages/Segments.php
+++ b/lib/AdminPages/Pages/Segments.php
@@ -12,12 +12,12 @@ class Segments {
   /** @var PageLimit */
   private $listing_page_limit;
 
-  function __construct(PageRenderer $page_renderer, PageLimit $listing_page_limit) {
+  public function __construct(PageRenderer $page_renderer, PageLimit $listing_page_limit) {
     $this->page_renderer = $page_renderer;
     $this->listing_page_limit = $listing_page_limit;
   }
 
-  function render() {
+  public function render() {
     $data = [];
     $data['items_per_page'] = $this->listing_page_limit->getLimitPerPage('segments');
     $this->page_renderer->displayPage('segments.html', $data);
diff --git a/lib/AdminPages/Pages/Settings.php b/lib/AdminPages/Pages/Settings.php
index ceee820db3..5110d0f5c8 100644
--- a/lib/AdminPages/Pages/Settings.php
+++ b/lib/AdminPages/Pages/Settings.php
@@ -41,7 +41,7 @@ class Settings {
   /** @var Installation */
   private $installation;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     SettingsController $settings,
     WooCommerceHelper $woocommerce_helper,
@@ -59,7 +59,7 @@ class Settings {
     $this->captcha = $captcha;
   }
 
-  function render() {
+  public function render() {
     $settings = $this->settings->getAll();
     $flags = $this->getFlags();
 
diff --git a/lib/AdminPages/Pages/Subscribers.php b/lib/AdminPages/Pages/Subscribers.php
index 69abf4d8fd..9c2cc7250a 100644
--- a/lib/AdminPages/Pages/Subscribers.php
+++ b/lib/AdminPages/Pages/Subscribers.php
@@ -22,13 +22,13 @@ class Subscribers {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(PageRenderer $page_renderer, PageLimit $listing_page_limit, WPFunctions $wp) {
+  public function __construct(PageRenderer $page_renderer, PageLimit $listing_page_limit, WPFunctions $wp) {
     $this->page_renderer = $page_renderer;
     $this->listing_page_limit = $listing_page_limit;
     $this->wp = $wp;
   }
 
-  function render() {
+  public function render() {
     $data = [];
 
     $data['items_per_page'] = $this->listing_page_limit->getLimitPerPage('subscribers');
diff --git a/lib/AdminPages/Pages/SubscribersAPIKeyInvalid.php b/lib/AdminPages/Pages/SubscribersAPIKeyInvalid.php
index 0abb84ef26..3bd0547bc0 100644
--- a/lib/AdminPages/Pages/SubscribersAPIKeyInvalid.php
+++ b/lib/AdminPages/Pages/SubscribersAPIKeyInvalid.php
@@ -13,12 +13,12 @@ class SubscribersAPIKeyInvalid {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
+  public function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
     $this->page_renderer = $page_renderer;
     $this->wp = $wp;
   }
 
-  function render() {
+  public function render() {
     $this->page_renderer->displayPage('invalidkey.html', [
       'current_wp_user' => $this->wp->wpGetCurrentUser()->to_array(),
       'subscriber_count' => Subscriber::getTotalSubscribers(),
diff --git a/lib/AdminPages/Pages/SubscribersExport.php b/lib/AdminPages/Pages/SubscribersExport.php
index b78e6ee638..101e6b32cb 100644
--- a/lib/AdminPages/Pages/SubscribersExport.php
+++ b/lib/AdminPages/Pages/SubscribersExport.php
@@ -9,11 +9,11 @@ class SubscribersExport {
   /** @var PageRenderer */
   private $page_renderer;
 
-  function __construct(PageRenderer $page_renderer) {
+  public function __construct(PageRenderer $page_renderer) {
     $this->page_renderer = $page_renderer;
   }
 
-  function render() {
+  public function render() {
     $export = new ImportExportFactory(ImportExportFactory::EXPORT_ACTION);
     $data = $export->bootstrap();
     $data['sub_menu'] = 'mailpoet-subscribers';
diff --git a/lib/AdminPages/Pages/SubscribersImport.php b/lib/AdminPages/Pages/SubscribersImport.php
index 70258da9c6..6af20bc58b 100644
--- a/lib/AdminPages/Pages/SubscribersImport.php
+++ b/lib/AdminPages/Pages/SubscribersImport.php
@@ -15,12 +15,12 @@ class SubscribersImport {
   /** @var Installation */
   private $installation;
 
-  function __construct(PageRenderer $page_renderer, Installation $installation) {
+  public function __construct(PageRenderer $page_renderer, Installation $installation) {
     $this->page_renderer = $page_renderer;
     $this->installation = $installation;
   }
 
-  function render() {
+  public function render() {
     $import = new ImportExportFactory(ImportExportFactory::IMPORT_ACTION);
     $data = $import->bootstrap();
     $data = array_merge($data, [
diff --git a/lib/AdminPages/Pages/Update.php b/lib/AdminPages/Pages/Update.php
index 5fab38d8b6..8fd6d29f7e 100644
--- a/lib/AdminPages/Pages/Update.php
+++ b/lib/AdminPages/Pages/Update.php
@@ -20,13 +20,13 @@ class Update {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(PageRenderer $page_renderer, WPFunctions $wp, SettingsController $settings) {
+  public function __construct(PageRenderer $page_renderer, WPFunctions $wp, SettingsController $settings) {
     $this->page_renderer = $page_renderer;
     $this->wp = $wp;
     $this->settings = $settings;
   }
 
-  function render() {
+  public function render() {
     global $wp;
     $current_url = $this->wp->homeUrl(add_query_arg($wp->query_string, $wp->request));
     $redirect_url =
diff --git a/lib/AdminPages/Pages/WelcomeWizard.php b/lib/AdminPages/Pages/WelcomeWizard.php
index 44187e3560..373fa29ee1 100644
--- a/lib/AdminPages/Pages/WelcomeWizard.php
+++ b/lib/AdminPages/Pages/WelcomeWizard.php
@@ -28,7 +28,7 @@ class WelcomeWizard {
   /** @var FeaturesController */
   private $features_controller;
 
-  function __construct(
+  public function __construct(
     PageRenderer $page_renderer,
     SettingsController $settings,
     WooCommerceHelper $woocommerce_helper,
@@ -42,7 +42,7 @@ class WelcomeWizard {
     $this->features_controller = $features_controller;
   }
 
-  function render() {
+  public function render() {
     if ((bool)(defined('DOING_AJAX') && DOING_AJAX)) return;
     $data = [
       'is_mp2_migration_complete' => (bool)$this->settings->get(MP2Migrator::MIGRATION_COMPLETE_SETTING_KEY),
diff --git a/lib/AdminPages/Pages/WooCommerceListImport.php b/lib/AdminPages/Pages/WooCommerceListImport.php
index a5f7273fe2..c4b83c2130 100644
--- a/lib/AdminPages/Pages/WooCommerceListImport.php
+++ b/lib/AdminPages/Pages/WooCommerceListImport.php
@@ -13,12 +13,12 @@ class WooCommerceListImport {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
+  public function __construct(PageRenderer $page_renderer, WPFunctions $wp) {
     $this->page_renderer = $page_renderer;
     $this->wp = $wp;
   }
 
-  function render() {
+  public function render() {
     if ((bool)(defined('DOING_AJAX') && DOING_AJAX)) return;
     $data = [
       'finish_wizard_url' => $this->wp->adminUrl('admin.php?page=' . Menu::MAIN_PAGE_SLUG),
diff --git a/lib/Analytics/Analytics.php b/lib/Analytics/Analytics.php
index 0cec95f423..5c14bdf6eb 100644
--- a/lib/Analytics/Analytics.php
+++ b/lib/Analytics/Analytics.php
@@ -28,7 +28,7 @@ class Analytics {
   }
 
   /** @return array|null */
-  function generateAnalytics() {
+  public function generateAnalytics() {
     if ($this->shouldSend()) {
       $data = $this->wp->applyFilters(self::ANALYTICS_FILTER, $this->reporter->getData());
       $this->recordDataSent();
@@ -38,12 +38,12 @@ class Analytics {
   }
 
   /** @return boolean */
-  function isEnabled() {
+  public function isEnabled() {
     $analytics_settings = $this->settings->get('analytics', []);
     return !empty($analytics_settings['enabled']) === true;
   }
 
-  function setPublicId($new_public_id) {
+  public function setPublicId($new_public_id) {
     $current_public_id = $this->settings->get('public_id');
     if ($current_public_id !== $new_public_id) {
       $this->settings->set('public_id', $new_public_id);
@@ -54,7 +54,7 @@ class Analytics {
   }
 
   /** @return string */
-  function getPublicId() {
+  public function getPublicId() {
     $public_id = $this->settings->get('public_id', '');
     // if we didn't get the user public_id from the shop yet : we create one based on mixpanel distinct_id
     if (empty($public_id) && !empty($_COOKIE['mixpanel_distinct_id'])) {
@@ -71,7 +71,7 @@ class Analytics {
    * Returns true if a the public_id was added and update new_public_id to false
    * @return boolean
    */
-  function isPublicIdNew() {
+  public function isPublicIdNew() {
     $new_public_id = $this->settings->get('new_public_id');
     if ($new_public_id === 'true') {
       $this->settings->set('new_public_id', 'false');
diff --git a/lib/Analytics/Reporter.php b/lib/Analytics/Reporter.php
index 53bc86d205..3139091389 100644
--- a/lib/Analytics/Reporter.php
+++ b/lib/Analytics/Reporter.php
@@ -26,7 +26,7 @@ class Reporter {
     $this->woocommerce_helper = $woocommerce_helper;
   }
 
-  function getData() {
+  public function getData() {
     global $wpdb, $wp_version, $woocommerce;
     $mta = $this->settings->get('mta', []);
     $newsletters = Newsletter::getAnalytics();
@@ -111,7 +111,7 @@ class Reporter {
     return $result;
   }
 
-  function getTrackingData() {
+  public function getTrackingData() {
     $newsletters = Newsletter::getAnalytics();
     $segments = Segment::getAnalytics();
     $mta = $this->settings->get('mta', []);
diff --git a/lib/AutomaticEmails/AutomaticEmails.php b/lib/AutomaticEmails/AutomaticEmails.php
index 588ed4dfc7..25016c78d7 100644
--- a/lib/AutomaticEmails/AutomaticEmails.php
+++ b/lib/AutomaticEmails/AutomaticEmails.php
@@ -16,11 +16,11 @@ class AutomaticEmails {
     'WooCommerce',
   ];
 
-  function __construct() {
+  public function __construct() {
     $this->wp = new WPFunctions;
   }
 
-  function init() {
+  public function init() {
     foreach ($this->available_groups as $group) {
       $group_class = sprintf(
         '%1$s\%2$s\%2$s',
@@ -44,7 +44,7 @@ class AutomaticEmails {
     }
   }
 
-  function getAutomaticEmails() {
+  public function getAutomaticEmails() {
     global $wp_filter;
 
     $registered_groups = preg_grep('!^' . self::FILTER_PREFIX . '(.*?)$!', array_keys($wp_filter));
@@ -70,7 +70,7 @@ class AutomaticEmails {
     return $automatic_emails;
   }
 
-  function getAutomaticEmailBySlug($email_slug) {
+  public function getAutomaticEmailBySlug($email_slug) {
     $automatic_emails = $this->getAutomaticEmails();
 
     if (empty($automatic_emails)) return null;
@@ -82,7 +82,7 @@ class AutomaticEmails {
     return null;
   }
 
-  function getAutomaticEmailEventBySlug($email_slug, $event_slug) {
+  public function getAutomaticEmailEventBySlug($email_slug, $event_slug) {
     $automatic_email = $this->getAutomaticEmailBySlug($email_slug);
 
     if (empty($automatic_email)) return null;
@@ -94,7 +94,7 @@ class AutomaticEmails {
     return null;
   }
 
-  function validateAutomaticEmailDataFields(array $automatic_email) {
+  public function validateAutomaticEmailDataFields(array $automatic_email) {
     $required_fields = [
       'slug',
       'title',
@@ -109,7 +109,7 @@ class AutomaticEmails {
     return true;
   }
 
-  function validateAutomaticEmailEventsDataFields(array $automatic_email_events) {
+  public function validateAutomaticEmailEventsDataFields(array $automatic_email_events) {
     $required_fields = [
       'slug',
       'title',
@@ -125,7 +125,7 @@ class AutomaticEmails {
     return true;
   }
 
-  function unregisterAutomaticEmails() {
+  public function unregisterAutomaticEmails() {
     global $wp_filter;
 
     $registered_groups = preg_grep('!^' . self::FILTER_PREFIX . '(.*?)$!', array_keys($wp_filter));
diff --git a/lib/AutomaticEmails/WooCommerce/Events/AbandonedCart.php b/lib/AutomaticEmails/WooCommerce/Events/AbandonedCart.php
index d130f9ee16..1d5e9e31d9 100644
--- a/lib/AutomaticEmails/WooCommerce/Events/AbandonedCart.php
+++ b/lib/AutomaticEmails/WooCommerce/Events/AbandonedCart.php
@@ -29,7 +29,7 @@ class AbandonedCart {
   /** @var AutomaticEmailScheduler */
   private $scheduler;
 
-  function __construct() {
+  public function __construct() {
     $this->wp = WPFunctions::get();
     $this->woo_commerce_helper = new WooCommerceHelper();
     $this->cookies = new Cookies();
@@ -37,7 +37,7 @@ class AbandonedCart {
     $this->scheduler = new AutomaticEmailScheduler();
   }
 
-  function getEventDetails() {
+  public function getEventDetails() {
     return [
       'slug' => self::SLUG,
       'title' => WPFunctions::get()->_x('Abandoned Shopping Cart', 'This is the name of a type of automatic email for ecommerce. Those emails are sent automatically when a customer adds product to his shopping cart but never complete the checkout process.', 'mailpoet'),
@@ -73,7 +73,7 @@ class AbandonedCart {
     ];
   }
 
-  function init() {
+  public function init() {
     if (!$this->woo_commerce_helper->isWooCommerceActive()) {
       return;
     }
@@ -127,7 +127,7 @@ class AbandonedCart {
     );
   }
 
-  function handleCartChange() {
+  public function handleCartChange() {
     $cart = $this->woo_commerce_helper->WC()->cart;
     if ($cart && !$cart->is_empty()) {
       $this->scheduleAbandonedCartEmail();
@@ -137,7 +137,7 @@ class AbandonedCart {
     }
   }
 
-  function trackPageVisit() {
+  public function trackPageVisit() {
     // on page visit reschedule all currently scheduled (not yet sent) emails for given subscriber
     // (it tracks at most once per minute to avoid processing many calls at the same time, i.e. AJAX)
     $this->page_visit_tracker->trackVisit(function () {
diff --git a/lib/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTracker.php b/lib/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTracker.php
index fd91ea345d..06d9f97b53 100644
--- a/lib/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTracker.php
+++ b/lib/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTracker.php
@@ -20,17 +20,17 @@ class AbandonedCartPageVisitTracker {
   /** @var Cookies */
   private $cookies;
 
-  function __construct(WPFunctions $wp, WooCommerceHelper $woo_commerce_helper, Cookies $cookies) {
+  public function __construct(WPFunctions $wp, WooCommerceHelper $woo_commerce_helper, Cookies $cookies) {
     $this->wp = $wp;
     $this->woo_commerce_helper = $woo_commerce_helper;
     $this->cookies = $cookies;
   }
 
-  function startTracking() {
+  public function startTracking() {
     $this->saveLastVisitTimestamp();
   }
 
-  function trackVisit(callable $onTrackCallback = null) {
+  public function trackVisit(callable $onTrackCallback = null) {
     // track at most once per minute to avoid processing many calls at the same time, i.e. AJAX
     $last_visit_timestamp = $this->loadLastVisitTimestamp();
     $minute_ago_timestamp = Carbon::now()->getTimestamp() - 60;
@@ -42,7 +42,7 @@ class AbandonedCartPageVisitTracker {
     }
   }
 
-  function stopTracking() {
+  public function stopTracking() {
     $this->removeLastVisitTimestamp();
   }
 
diff --git a/lib/AutomaticEmails/WooCommerce/Events/FirstPurchase.php b/lib/AutomaticEmails/WooCommerce/Events/FirstPurchase.php
index 09d1797b51..88d190d4fa 100644
--- a/lib/AutomaticEmails/WooCommerce/Events/FirstPurchase.php
+++ b/lib/AutomaticEmails/WooCommerce/Events/FirstPurchase.php
@@ -26,7 +26,7 @@ class FirstPurchase {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function __construct(WCHelper $helper = null) {
+  public function __construct(WCHelper $helper = null) {
     if ($helper === null) {
       $helper = new WCHelper();
     }
@@ -35,7 +35,7 @@ class FirstPurchase {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addFilter('mailpoet_newsletter_shortcode', [
       $this,
       'handleOrderTotalShortcode',
@@ -56,7 +56,7 @@ class FirstPurchase {
     }
   }
 
-  function getEventDetails() {
+  public function getEventDetails() {
     return [
       'slug' => self::SLUG,
       'title' => WPFunctions::get()->__('First Purchase', 'mailpoet'),
@@ -79,7 +79,7 @@ class FirstPurchase {
     ];
   }
 
-  function handleOrderDateShortcode($shortcode, $newsletter, $subscriber, $queue) {
+  public function handleOrderDateShortcode($shortcode, $newsletter, $subscriber, $queue) {
     $result = $shortcode;
     if ($shortcode === self::ORDER_DATE_SHORTCODE) {
       $default_value = WPFunctions::get()->dateI18n(get_option('date_format'));
@@ -102,7 +102,7 @@ class FirstPurchase {
     return $result;
   }
 
-  function handleOrderTotalShortcode($shortcode, $newsletter, $subscriber, $queue) {
+  public function handleOrderTotalShortcode($shortcode, $newsletter, $subscriber, $queue) {
     $result = $shortcode;
     if ($shortcode === self::ORDER_TOTAL_SHORTCODE) {
       $default_value = $this->helper->wcPrice(0);
@@ -125,7 +125,7 @@ class FirstPurchase {
     return $result;
   }
 
-  function scheduleEmailWhenOrderIsPlaced($order_id) {
+  public function scheduleEmailWhenOrderIsPlaced($order_id) {
     $order_details = $this->helper->wcGetOrder($order_id);
     if (!$order_details || !$order_details->get_billing_email()) {
       $this->logger_factory->getLogger(self::SLUG)->addInfo(
@@ -178,7 +178,7 @@ class FirstPurchase {
     $this->scheduler->scheduleAutomaticEmail(WooCommerce::SLUG, self::SLUG, $check_email_was_not_scheduled, $subscriber->id, $meta);
   }
 
-  function getCustomerOrderCount($customer_email) {
+  public function getCustomerOrderCount($customer_email) {
     // registered user
     $user = WPFunctions::get()->getUserBy('email', $customer_email);
     if ($user) {
diff --git a/lib/AutomaticEmails/WooCommerce/Events/PurchasedInCategory.php b/lib/AutomaticEmails/WooCommerce/Events/PurchasedInCategory.php
index 66f7a12761..be0cbdc345 100644
--- a/lib/AutomaticEmails/WooCommerce/Events/PurchasedInCategory.php
+++ b/lib/AutomaticEmails/WooCommerce/Events/PurchasedInCategory.php
@@ -23,7 +23,7 @@ class PurchasedInCategory {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function __construct(WCHelper $woocommerce_helper = null) {
+  public function __construct(WCHelper $woocommerce_helper = null) {
     if ($woocommerce_helper === null) {
       $woocommerce_helper = new WCHelper();
     }
@@ -32,7 +32,7 @@ class PurchasedInCategory {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function getEventDetails() {
+  public function getEventDetails() {
     return [
       'slug' => self::SLUG,
       'title' => _x('Purchased In This Category', 'This is the name of a type for automatic email for ecommerce. Those emails are sent automatically every time a customer buys for the first time a product in a given category', 'mailpoet'),
@@ -49,7 +49,7 @@ class PurchasedInCategory {
     ];
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->removeAllFilters('woocommerce_product_purchased_get_categories');
     WPFunctions::get()->addFilter(
       'woocommerce_product_purchased_get_categories',
@@ -67,7 +67,7 @@ class PurchasedInCategory {
     }
   }
 
-  function getCategories($search_query) {
+  public function getCategories($search_query) {
     $args = [
       'taxonomy' => 'product_cat',
       'search' => $search_query,
@@ -86,7 +86,7 @@ class PurchasedInCategory {
     }, $all_categories);
   }
 
-  function scheduleEmail($order_id) {
+  public function scheduleEmail($order_id) {
     $order_details = $this->woocommerce_helper->wcGetOrder($order_id);
     if (!$order_details || !$order_details->get_billing_email()) {
       $this->logger_factory->getLogger(self::SLUG)->addInfo(
diff --git a/lib/AutomaticEmails/WooCommerce/Events/PurchasedProduct.php b/lib/AutomaticEmails/WooCommerce/Events/PurchasedProduct.php
index 57e4c66840..103edad7f3 100644
--- a/lib/AutomaticEmails/WooCommerce/Events/PurchasedProduct.php
+++ b/lib/AutomaticEmails/WooCommerce/Events/PurchasedProduct.php
@@ -24,7 +24,7 @@ class PurchasedProduct {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function __construct(WCHelper $helper = null) {
+  public function __construct(WCHelper $helper = null) {
     if ($helper === null) {
       $helper = new WCHelper();
     }
@@ -33,7 +33,7 @@ class PurchasedProduct {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->removeAllFilters('woocommerce_product_purchased_get_products');
     WPFunctions::get()->addFilter(
       'woocommerce_product_purchased_get_products',
@@ -53,7 +53,7 @@ class PurchasedProduct {
     }
   }
 
-  function getEventDetails() {
+  public function getEventDetails() {
     return [
       'slug' => self::SLUG,
       'title' => WPFunctions::get()->__('Purchased This Product', 'mailpoet'),
@@ -70,7 +70,7 @@ class PurchasedProduct {
     ];
   }
 
-  function getProducts($product_search_query) {
+  public function getProducts($product_search_query) {
     $args = [
       'post_type' => 'product',
       'post_status' => 'publish',
@@ -96,7 +96,7 @@ class PurchasedProduct {
     return $woocommerce_products;
   }
 
-  function scheduleEmailWhenProductIsPurchased($order_id) {
+  public function scheduleEmailWhenProductIsPurchased($order_id) {
     $order_details = $this->helper->wcGetOrder($order_id);
     if (!$order_details || !$order_details->get_billing_email()) {
       $this->logger_factory->getLogger(self::SLUG)->addInfo(
diff --git a/lib/AutomaticEmails/WooCommerce/WooCommerce.php b/lib/AutomaticEmails/WooCommerce/WooCommerce.php
index 1f406de2c8..56e244b36d 100644
--- a/lib/AutomaticEmails/WooCommerce/WooCommerce.php
+++ b/lib/AutomaticEmails/WooCommerce/WooCommerce.php
@@ -23,13 +23,13 @@ class WooCommerce {
   private $_woocommerce_enabled;
   private $wp;
 
-  function __construct() {
+  public function __construct() {
     $this->wp = new WPFunctions;
     $this->woocommerce_helper = new WooCommerceHelper();
     $this->_woocommerce_enabled = $this->isWoocommerceEnabled();
   }
 
-  function init() {
+  public function init() {
     $this->wp->addFilter(
       AutomaticEmails::FILTER_PREFIX . self::SLUG,
       [
@@ -46,7 +46,7 @@ class WooCommerce {
     );
   }
 
-  function setupGroup() {
+  public function setupGroup() {
     return [
       'slug' => self::SLUG,
       'title' => WPFunctions::get()->__('WooCommerce', 'mailpoet'),
@@ -55,7 +55,7 @@ class WooCommerce {
     ];
   }
 
-  function setupEvents($events) {
+  public function setupEvents($events) {
     $custom_event_details = (!$this->_woocommerce_enabled) ? [
       'actionButtonTitle' => WPFunctions::get()->__('WooCommerce is required', 'mailpoet'),
       'actionButtonLink' => 'https://wordpress.org/plugins/woocommerce/',
@@ -94,7 +94,7 @@ class WooCommerce {
     return $events;
   }
 
-  function isWoocommerceEnabled() {
+  public function isWoocommerceEnabled() {
     return $this->woocommerce_helper->isWooCommerceActive();
   }
 
diff --git a/lib/Config/AccessControl.php b/lib/Config/AccessControl.php
index 970e06ee72..88e4e85a57 100644
--- a/lib/Config/AccessControl.php
+++ b/lib/Config/AccessControl.php
@@ -15,7 +15,7 @@ class AccessControl {
   const NO_ACCESS_RESTRICTION = 'mailpoet_no_access_restriction';
   const ALL_ROLES_ACCESS = 'mailpoet_all_roles_access';
 
-  function getDefaultPermissions() {
+  public function getDefaultPermissions() {
     return [
       self::PERMISSION_ACCESS_PLUGIN_ADMIN => WPFunctions::get()->applyFilters(
         'mailpoet_permission_access_plugin_admin',
@@ -64,7 +64,7 @@ class AccessControl {
     ];
   }
 
-  function getPermissionLabels() {
+  public function getPermissionLabels() {
     return [
       self::PERMISSION_ACCESS_PLUGIN_ADMIN => WPFunctions::get()->__('Admin menu item', 'mailpoet'),
       self::PERMISSION_MANAGE_SETTINGS => WPFunctions::get()->__('Manage settings', 'mailpoet'),
@@ -76,7 +76,7 @@ class AccessControl {
     ];
   }
 
-  function validatePermission($permission) {
+  public function validatePermission($permission) {
     if ($permission === self::NO_ACCESS_RESTRICTION) return true;
     if ($permission === self::ALL_ROLES_ACCESS) {
       $capabilities = array_keys($this->getDefaultPermissions());
diff --git a/lib/Config/Activator.php b/lib/Config/Activator.php
index f16677f2dd..8ce45a0a6c 100644
--- a/lib/Config/Activator.php
+++ b/lib/Config/Activator.php
@@ -12,12 +12,12 @@ class Activator {
   /** @var Populator */
   private $populator;
 
-  function __construct(SettingsController $settings, Populator $populator) {
+  public function __construct(SettingsController $settings, Populator $populator) {
     $this->settings = $settings;
     $this->populator = $populator;
   }
 
-  function activate() {
+  public function activate() {
     $migrator = new Migrator();
     $migrator->up();
 
@@ -28,7 +28,7 @@ class Activator {
     $caps->setupWPCapabilities();
   }
 
-  function deactivate() {
+  public function deactivate() {
     $migrator = new Migrator();
     $migrator->down();
 
@@ -36,7 +36,7 @@ class Activator {
     $caps->removeWPCapabilities();
   }
 
-  function updateDbVersion() {
+  public function updateDbVersion() {
     try {
       $current_db_version = $this->settings->get('db_version');
     } catch (\Exception $e) {
diff --git a/lib/Config/Capabilities.php b/lib/Config/Capabilities.php
index b1b9ce71bd..4a5c6be1ab 100644
--- a/lib/Config/Capabilities.php
+++ b/lib/Config/Capabilities.php
@@ -14,7 +14,7 @@ class Capabilities {
   /** @var AccessControl */
   private $access_control;
 
-  function __construct($renderer = null, WPFunctions $wp = null) {
+  public function __construct($renderer = null, WPFunctions $wp = null) {
     if ($renderer !== null) {
       $this->renderer = $renderer;
     }
@@ -25,11 +25,11 @@ class Capabilities {
     $this->access_control = new AccessControl;
   }
 
-  function init() {
+  public function init() {
     $this->setupMembersCapabilities();
   }
 
-  function setupWPCapabilities() {
+  public function setupWPCapabilities() {
     $permissions = $this->access_control->getDefaultPermissions();
     $role_objects = [];
     foreach ($permissions as $name => $roles) {
@@ -43,7 +43,7 @@ class Capabilities {
     }
   }
 
-  function removeWPCapabilities() {
+  public function removeWPCapabilities() {
     $permissions = $this->access_control->getDefaultPermissions();
     $role_objects = [];
     foreach ($permissions as $name => $roles) {
@@ -57,20 +57,20 @@ class Capabilities {
     }
   }
 
-  function setupMembersCapabilities() {
+  public function setupMembersCapabilities() {
     $this->wp->addAction('admin_enqueue_scripts', [$this, 'enqueueMembersStyles']);
     $this->wp->addAction('members_register_cap_groups', [$this, 'registerMembersCapGroup']);
     $this->wp->addAction('members_register_caps', [$this, 'registerMembersCapabilities']);
   }
 
-  function enqueueMembersStyles() {
+  public function enqueueMembersStyles() {
     WPFunctions::get()->wpEnqueueStyle(
       'mailpoet-admin-global',
       Env::$assets_url . '/dist/css/' . $this->renderer->getCssAsset('adminGlobal.css')
     );
   }
 
-  function registerMembersCapGroup() {
+  public function registerMembersCapGroup() {
     members_register_cap_group(
       self::MEMBERS_CAP_GROUP_NAME,
       [
@@ -82,14 +82,14 @@ class Capabilities {
     );
   }
 
-  function registerMembersCapabilities() {
+  public function registerMembersCapabilities() {
     $permissions = $this->access_control->getPermissionLabels();
     foreach ($permissions as $name => $label) {
       $this->registerMembersCapability($name, $label);
     }
   }
 
-  function registerMembersCapability($name, $label) {
+  public function registerMembersCapability($name, $label) {
     members_register_cap(
       $name,
       [
diff --git a/lib/Config/Changelog.php b/lib/Config/Changelog.php
index 19c288e936..a5c57f6d71 100644
--- a/lib/Config/Changelog.php
+++ b/lib/Config/Changelog.php
@@ -23,7 +23,7 @@ class Changelog {
   /** @var MP2Migrator */
   private $mp2_migrator;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     WPFunctions $wp,
     Helper $wooCommerceHelper,
@@ -37,7 +37,7 @@ class Changelog {
     $this->mp2_migrator = $mp2_migrator;
   }
 
-  function init() {
+  public function init() {
     $doing_ajax = (bool)(defined('DOING_AJAX') && DOING_AJAX);
 
     // don't run any check when it's an ajax request
@@ -60,7 +60,7 @@ class Changelog {
     );
   }
 
-  function check() {
+  public function check() {
     $version = $this->settings->get('version');
     $this->checkMp2Migration($version);
     if ($version === null) {
diff --git a/lib/Config/Database.php b/lib/Config/Database.php
index 9e6b3dbdb8..0be75ebe59 100644
--- a/lib/Config/Database.php
+++ b/lib/Config/Database.php
@@ -6,17 +6,17 @@ use MailPoetVendor\Idiorm\ORM;
 use PDO;
 
 class Database {
-  function init(PDO $pdo) {
+  public function init(PDO $pdo) {
     ORM::setDb($pdo);
     $this->setupLogging();
     $this->defineTables();
   }
 
-  function setupLogging() {
+  public function setupLogging() {
     ORM::configure('logging', WP_DEBUG);
   }
 
-  function defineTables() {
+  public function defineTables() {
     if (!defined('MP_SETTINGS_TABLE')) {
       define('MP_SETTINGS_TABLE', Env::$db_prefix . 'settings');
       define('MP_SEGMENTS_TABLE', Env::$db_prefix . 'segments');
diff --git a/lib/Config/DatabaseInitializer.php b/lib/Config/DatabaseInitializer.php
index b0e681b57c..3c4bbadd57 100644
--- a/lib/Config/DatabaseInitializer.php
+++ b/lib/Config/DatabaseInitializer.php
@@ -8,11 +8,11 @@ use MailPoetVendor\Psr\Container\ContainerInterface;
 class DatabaseInitializer {
   private $di_container;
 
-  function __construct(ContainerInterface $di_container) {
+  public function __construct(ContainerInterface $di_container) {
     $this->di_container = $di_container;
   }
 
-  function initializeConnection() {
+  public function initializeConnection() {
     $connection = $this->di_container->get(Connection::class);
 
     // pass the same PDO connection to legacy Database object
diff --git a/lib/Config/Env.php b/lib/Config/Env.php
index 867e49f372..60d3bf04f2 100644
--- a/lib/Config/Env.php
+++ b/lib/Config/Env.php
@@ -36,7 +36,7 @@ class Env {
   static $db_charset_collate;
   static $db_timezone_offset;
 
-  static function init($file, $version, $db_host, $db_user, $db_password, $db_name) {
+  public static function init($file, $version, $db_host, $db_user, $db_password, $db_name) {
     self::$version = $version;
     self::$file = $file;
     self::$path = dirname(self::$file);
@@ -82,7 +82,7 @@ class Env {
     self::$db_timezone_offset = self::getDbTimezoneOffset();
   }
 
-  static function getDbTimezoneOffset($offset = false) {
+  public static function getDbTimezoneOffset($offset = false) {
     $offset = ($offset) ? $offset : WPFunctions::get()->getOption('gmt_offset');
     $mins = $offset * 60;
     $sgn = ($mins < 0 ? -1 : 1);
diff --git a/lib/Config/Hooks.php b/lib/Config/Hooks.php
index dc9f81e34f..36fbc48d46 100644
--- a/lib/Config/Hooks.php
+++ b/lib/Config/Hooks.php
@@ -58,7 +58,7 @@ class Hooks {
   /** @var DynamicSegmentHooks */
   private $dynamic_segment_hooks;
 
-  function __construct(
+  public function __construct(
     Form $subscription_form,
     Comment $subscription_comment,
     Manage $subscription_manage,
@@ -88,7 +88,7 @@ class Hooks {
     $this->dynamic_segment_hooks = $dynamic_segment_hooks;
   }
 
-  function init() {
+  public function init() {
     $this->setupWPUsers();
     $this->setupWooCommerceUsers();
     $this->setupWooCommercePurchases();
@@ -101,11 +101,11 @@ class Hooks {
     $this->dynamic_segment_hooks->init();
   }
 
-  function initEarlyHooks() {
+  public function initEarlyHooks() {
     $this->setupMailer();
   }
 
-  function setupSubscriptionEvents() {
+  public function setupSubscriptionEvents() {
 
     $subscribe = $this->settings->get('subscribe', []);
     // Subscribe in comments
@@ -197,7 +197,7 @@ class Hooks {
     );
   }
 
-  function setupMailer() {
+  public function setupMailer() {
     $this->wp->addAction('plugins_loaded', [
       $this->wordpress_mailer_replacer,
       'replaceWordPressMailer',
@@ -212,7 +212,7 @@ class Hooks {
     ]);
   }
 
-  function setupWooCommerceSubscriptionEvents() {
+  public function setupWooCommerceSubscriptionEvents() {
     $woocommerce = $this->settings->get('woocommerce', []);
     // WooCommerce: subscribe on checkout
     if (!empty($woocommerce['optin_on_checkout']['enabled'])) {
@@ -230,7 +230,7 @@ class Hooks {
     );
   }
 
-  function setupWPUsers() {
+  public function setupWPUsers() {
     // WP Users synchronization
     $this->wp->addAction(
       'user_register',
@@ -265,14 +265,14 @@ class Hooks {
     );
   }
 
-  function setupWooCommerceSettings() {
+  public function setupWooCommerceSettings() {
     $this->wp->addAction('woocommerce_settings_start', [
       $this->woocommerce_settings,
       'disableWooCommerceSettings',
     ]);
   }
 
-  function setupWooCommerceUsers() {
+  public function setupWooCommerceUsers() {
     // WooCommerce Customers synchronization
     $this->wp->addAction(
       'woocommerce_new_customer',
@@ -301,7 +301,7 @@ class Hooks {
     );
   }
 
-  function setupWooCommercePurchases() {
+  public function setupWooCommercePurchases() {
     // use both 'processing' and 'completed' states since payment hook and 'processing' status
     // may be skipped with some payment methods (cheque) or when state transitioned manually
     $accepted_order_states = WPFunctions::get()->applyFilters(
@@ -319,7 +319,7 @@ class Hooks {
     }
   }
 
-  function setupImageSize() {
+  public function setupImageSize() {
     $this->wp->addFilter(
       'image_size_names_choose',
       [$this, 'appendImageSize'],
@@ -327,13 +327,13 @@ class Hooks {
     );
   }
 
-  function appendImageSize($sizes) {
+  public function appendImageSize($sizes) {
     return array_merge($sizes, [
       'mailpoet_newsletter_max' => WPFunctions::get()->__('MailPoet Newsletter', 'mailpoet'),
     ]);
   }
 
-  function setupListing() {
+  public function setupListing() {
     $this->wp->addFilter(
       'set-screen-option',
       [$this, 'setScreenOption'],
@@ -341,7 +341,7 @@ class Hooks {
     );
   }
 
-  function setScreenOption($status, $option, $value) {
+  public function setScreenOption($status, $option, $value) {
     if (preg_match('/^mailpoet_(.*)_per_page$/', $option)) {
       return $value;
     } else {
@@ -349,7 +349,7 @@ class Hooks {
     }
   }
 
-  function setupPostNotifications() {
+  public function setupPostNotifications() {
     $this->wp->addAction(
       'transition_post_status',
       [$this->post_notification_scheduler, 'transitionHook'],
diff --git a/lib/Config/Initializer.php b/lib/Config/Initializer.php
index 3a8d453c11..a0ec0224d7 100644
--- a/lib/Config/Initializer.php
+++ b/lib/Config/Initializer.php
@@ -70,7 +70,7 @@ class Initializer {
 
   const INITIALIZED = 'MAILPOET_INITIALIZED';
 
-  function __construct(
+  public function __construct(
     RendererFactory $renderer_factory,
     AccessControl $access_control,
     API $api,
@@ -104,7 +104,7 @@ class Initializer {
       $this->wc_helper = $wc_helper;
   }
 
-  function init() {
+  public function init() {
     // load translations
     $this->setupLocalizer();
 
@@ -162,11 +162,11 @@ class Initializer {
     $this->hooks->initEarlyHooks();
   }
 
-  function runActivator() {
+  public function runActivator() {
     return $this->activator->activate();
   }
 
-  function preInitialize() {
+  public function preInitialize() {
     try {
       $this->renderer = $this->renderer_factory->getRenderer();
       $this->setupWidget();
@@ -177,11 +177,11 @@ class Initializer {
     }
   }
 
-  function setupWidget() {
+  public function setupWidget() {
     WPFunctions::get()->registerWidget('\MailPoet\Form\Widget');
   }
 
-  function initialize() {
+  public function initialize() {
     try {
       $this->maybeDbUpdate();
       $this->setupInstaller();
@@ -212,7 +212,7 @@ class Initializer {
     define(self::INITIALIZED, true);
   }
 
-  function maybeDbUpdate() {
+  public function maybeDbUpdate() {
     try {
       $current_db_version = $this->settings->get('db_version');
     } catch (\Exception $e) {
@@ -225,14 +225,14 @@ class Initializer {
     }
   }
 
-  function setupInstaller() {
+  public function setupInstaller() {
     $installer = new Installer(
       Installer::PREMIUM_PLUGIN_SLUG
     );
     $installer->init();
   }
 
-  function setupUpdater() {
+  public function setupUpdater() {
     $slug = Installer::PREMIUM_PLUGIN_SLUG;
     $plugin_file = Installer::getPluginFile($slug);
     if (empty($plugin_file) || !defined('MAILPOET_PREMIUM_VERSION')) {
@@ -246,37 +246,37 @@ class Initializer {
     $updater->init();
   }
 
-  function setupLocalizer() {
+  public function setupLocalizer() {
     $localizer = new Localizer();
     $localizer->init();
   }
 
-  function setupCapabilities() {
+  public function setupCapabilities() {
     $caps = new Capabilities($this->renderer);
     $caps->init();
   }
 
-  function setupShortcodes() {
+  public function setupShortcodes() {
     $this->shortcodes->init();
   }
 
-  function setupImages() {
+  public function setupImages() {
     WPFunctions::get()->addImageSize('mailpoet_newsletter_max', Env::NEWSLETTER_CONTENT_WIDTH);
   }
 
-  function setupCronTrigger() {
+  public function setupCronTrigger() {
     // setup cron trigger only outside of cli environment
     if (php_sapi_name() !== 'cli') {
       $this->cron_trigger->init();
     }
   }
 
-  function setupConflictResolver() {
+  public function setupConflictResolver() {
     $conflict_resolver = new ConflictResolver();
     $conflict_resolver->init();
   }
 
-  function postInitialize() {
+  public function postInitialize() {
     if (!defined(self::INITIALIZED)) return;
     try {
       $this->api->init();
@@ -287,38 +287,38 @@ class Initializer {
     }
   }
 
-  function setupUserLocale() {
+  public function setupUserLocale() {
     if (get_user_locale() === WPFunctions::get()->getLocale()) return;
     WPFunctions::get()->unloadTextdomain(Env::$plugin_name);
     $localizer = new Localizer();
     $localizer->init();
   }
 
-  function setupPages() {
+  public function setupPages() {
     $pages = new \MailPoet\Settings\Pages();
     $pages->init();
   }
 
-  function setupPrivacyPolicy() {
+  public function setupPrivacyPolicy() {
     $privacy_policy = new PrivacyPolicy();
     $privacy_policy->init();
   }
 
-  function setupPersonalDataExporters() {
+  public function setupPersonalDataExporters() {
     $exporters = new PersonalDataExporters();
     $exporters->init();
   }
 
-  function setupPersonalDataErasers() {
+  public function setupPersonalDataErasers() {
     $erasers = new PersonalDataErasers();
     $erasers->init();
   }
 
-  function setupPermanentNotices() {
+  public function setupPermanentNotices() {
     $this->permanent_notices->init();
   }
 
-  function handleFailedInitialization($exception) {
+  public function handleFailedInitialization($exception) {
     // check if we are able to add pages at this point
     if (function_exists('wp_get_current_user')) {
       Menu::addErrorPage($this->access_control);
@@ -326,12 +326,12 @@ class Initializer {
     return WPNotice::displayError($exception);
   }
 
-  function setupDeactivationSurvey() {
+  public function setupDeactivationSurvey() {
     $survey = new DeactivationSurvey($this->renderer);
     $survey->init();
   }
 
-  function setupAutomaticEmails() {
+  public function setupAutomaticEmails() {
     $automatic_emails = new AutomaticEmails();
     $automatic_emails->init();
     $this->automatic_emails = $automatic_emails->getAutomaticEmails();
@@ -358,7 +358,7 @@ class Initializer {
     }
   }
 
-  function includeAutomaticEmailsData() {
+  public function includeAutomaticEmailsData() {
     $data = [
       'automatic_emails' => $this->automatic_emails,
       'woocommerce_optin_on_checkout' => $this->settings->get('woocommerce.optin_on_checkout.enabled', false),
diff --git a/lib/Config/Installer.php b/lib/Config/Installer.php
index 37edd63bdc..c5b8c323cc 100644
--- a/lib/Config/Installer.php
+++ b/lib/Config/Installer.php
@@ -16,16 +16,16 @@ class Installer {
   /** @var SettingsController */
   private $settings;
 
-  function __construct($slug) {
+  public function __construct($slug) {
     $this->slug = $slug;
     $this->settings = SettingsController::getInstance();
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addFilter('plugins_api', [$this, 'getPluginInformation'], 10, 3);
   }
 
-  function getPluginInformation($data, $action = '', $args = null) {
+  public function getPluginInformation($data, $action = '', $args = null) {
     if ($action === 'plugin_information'
       && isset($args->slug)
       && $args->slug === $this->slug
@@ -36,7 +36,7 @@ class Installer {
     return $data;
   }
 
-  static function getPremiumStatus() {
+  public static function getPremiumStatus() {
     $slug = self::PREMIUM_PLUGIN_SLUG;
 
     $premium_plugin_active = License::getLicense();
@@ -54,12 +54,12 @@ class Installer {
     );
   }
 
-  static function isPluginInstalled($slug) {
+  public static function isPluginInstalled($slug) {
     $installed_plugin = self::getInstalledPlugin($slug);
     return !empty($installed_plugin);
   }
 
-  static function getPluginInstallationUrl($slug) {
+  public static function getPluginInstallationUrl($slug) {
     $install_url = WPFunctions::get()->addQueryArg(
       [
         'action'   => 'install-plugin',
@@ -71,7 +71,7 @@ class Installer {
     return $install_url;
   }
 
-  static function getPluginActivationUrl($slug) {
+  public static function getPluginActivationUrl($slug) {
     $plugin_file = self::getPluginFile($slug);
     if (empty($plugin_file)) {
       return false;
@@ -95,7 +95,7 @@ class Installer {
     return $installed_plugin;
   }
 
-  static function getPluginFile($slug) {
+  public static function getPluginFile($slug) {
     $plugin_file = false;
     $installed_plugin = self::getInstalledPlugin($slug);
     if (!empty($installed_plugin)) {
@@ -104,7 +104,7 @@ class Installer {
     return $plugin_file;
   }
 
-  function retrievePluginInformation() {
+  public function retrievePluginInformation() {
     $key = $this->settings->get(Bridge::PREMIUM_KEY_SETTING_NAME);
     $api = new API($key);
     $info = $api->getPluginInformation($this->slug);
diff --git a/lib/Config/Localizer.php b/lib/Config/Localizer.php
index 5c8a9fe3bc..d8ec4d54c3 100644
--- a/lib/Config/Localizer.php
+++ b/lib/Config/Localizer.php
@@ -5,12 +5,12 @@ namespace MailPoet\Config;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Localizer {
-  function init() {
+  public function init() {
     $this->loadGlobalText();
     $this->loadPluginText();
   }
 
-  function loadGlobalText() {
+  public function loadGlobalText() {
     $language_path = sprintf(
       '%s/%s-%s.mo',
       Env::$languages_path,
@@ -20,7 +20,7 @@ class Localizer {
     WPFunctions::get()->loadTextdomain(Env::$plugin_name, $language_path);
   }
 
-  function loadPluginText() {
+  public function loadPluginText() {
     WPFunctions::get()->loadPluginTextdomain(
       Env::$plugin_name,
       false,
@@ -28,7 +28,7 @@ class Localizer {
     );
   }
 
-  function locale() {
+  public function locale() {
     $locale = WPFunctions::get()->applyFilters(
       'plugin_locale',
       WPFunctions::get()->getUserLocale(),
@@ -37,7 +37,7 @@ class Localizer {
     return $locale;
   }
 
-  function forceLoadWebsiteLocaleText() {
+  public function forceLoadWebsiteLocaleText() {
     $language_path = sprintf(
       '%s/%s-%s.mo',
       Env::$languages_path,
diff --git a/lib/Config/Menu.php b/lib/Config/Menu.php
index 713069c890..17fb65c49e 100644
--- a/lib/Config/Menu.php
+++ b/lib/Config/Menu.php
@@ -47,7 +47,7 @@ class Menu {
   /** @var FeaturesController */
   private $features_controller;
 
-  function __construct(
+  public function __construct(
     AccessControl $access_control,
     WPFunctions $wp,
     ServicesChecker $services_checker,
@@ -61,7 +61,7 @@ class Menu {
     $this->container = $container;
   }
 
-  function init() {
+  public function init() {
     $this->checkMailPoetAPIKey();
     $this->checkPremiumKey();
 
@@ -74,7 +74,7 @@ class Menu {
     );
   }
 
-  function setup() {
+  public function setup() {
     if (!$this->access_control->validatePermission(AccessControl::PERMISSION_ACCESS_PLUGIN_ADMIN)) return;
     if (self::isOnMailPoetAdminPage()) {
       $this->wp->doAction('mailpoet_conflict_resolver_styles');
@@ -412,83 +412,83 @@ class Menu {
     );
   }
 
-  function disableWPEmojis() {
+  public function disableWPEmojis() {
     $this->wp->removeAction('admin_print_scripts', 'print_emoji_detection_script');
     $this->wp->removeAction('admin_print_styles', 'print_emoji_styles');
   }
 
-  function migration() {
+  public function migration() {
     $this->container->get(MP2Migration::class)->render();
   }
 
-  function welcomeWizard() {
+  public function welcomeWizard() {
     $this->container->get(WelcomeWizard::class)->render();
   }
 
-  function wooCommerceListImport() {
+  public function wooCommerceListImport() {
     $this->container->get(WooCommerceListImport::class)->render();
   }
 
-  function revenueTrackingPermission() {
+  public function revenueTrackingPermission() {
     $this->container->get(RevenueTrackingPermission::class)->render();
   }
 
-  function update() {
+  public function update() {
     $this->container->get(Update::class)->render();
   }
 
-  function premium() {
+  public function premium() {
     $this->container->get(Premium::class)->render();
   }
 
-  function settings() {
+  public function settings() {
     $this->container->get(Settings::class)->render();
   }
 
-  function help() {
+  public function help() {
     $this->container->get(Help::class)->render();
   }
 
-  function experimentalFeatures() {
+  public function experimentalFeatures() {
     $this->container->get(ExperimentalFeatures::class)->render();
   }
 
-  function subscribers() {
+  public function subscribers() {
     $this->container->get(Subscribers::class)->render();
   }
 
-  function segments() {
+  public function segments() {
     $this->container->get(Segments::class)->render();
   }
 
-  function dynamicSegments() {
+  public function dynamicSegments() {
     $this->container->get(DynamicSegments::class)->render();
   }
 
-  function forms() {
+  public function forms() {
     $this->container->get(Forms::class)->render();
   }
 
-  function newsletters() {
+  public function newsletters() {
     if (isset($this->mp_api_key_valid) && $this->mp_api_key_valid === false) {
       return $this->displayMailPoetAPIKeyInvalid();
     }
     $this->container->get(Newsletters::class)->render();
   }
 
-  function newletterEditor() {
+  public function newletterEditor() {
     $this->container->get(NewsletterEditor::class)->render();
   }
 
-  function import() {
+  public function import() {
     $this->container->get(SubscribersImport::class)->render();
   }
 
-  function export() {
+  public function export() {
     $this->container->get(SubscribersExport::class)->render();
   }
 
-  function formEditor() {
+  public function formEditor() {
     $this->container->get(FormEditor::class)->render();
   }
 
@@ -497,7 +497,7 @@ class Menu {
     exit;
   }
 
-  function setPageTitle($title) {
+  public function setPageTitle($title) {
     return sprintf(
       '%s - %s',
       $this->wp->__('MailPoet', 'mailpoet'),
@@ -505,7 +505,7 @@ class Menu {
     );
   }
 
-  static function isOnMailPoetAdminPage(array $exclude = null, $screen_id = null) {
+  public static function isOnMailPoetAdminPage(array $exclude = null, $screen_id = null) {
     if (is_null($screen_id)) {
       if (empty($_REQUEST['page'])) {
         return false;
@@ -526,7 +526,7 @@ class Menu {
    * This error page is used when the initialization is failed
    * to display admin notices only
    */
-  static function addErrorPage(AccessControl $access_control) {
+  public static function addErrorPage(AccessControl $access_control) {
     if (!self::isOnMailPoetAdminPage()) {
       return false;
     }
@@ -549,11 +549,11 @@ class Menu {
     );
   }
 
-  static function errorPageCallback() {
+  public static function errorPageCallback() {
     // Used for displaying admin notices only
   }
 
-  function checkMailPoetAPIKey(ServicesChecker $checker = null) {
+  public function checkMailPoetAPIKey(ServicesChecker $checker = null) {
     if (self::isOnMailPoetAdminPage()) {
       $show_notices = isset($_REQUEST['page'])
         && stripos($_REQUEST['page'], self::MAIN_PAGE_SLUG) === false;
@@ -562,7 +562,7 @@ class Menu {
     }
   }
 
-  function checkPremiumKey(ServicesChecker $checker = null) {
+  public function checkPremiumKey(ServicesChecker $checker = null) {
     $show_notices = isset($_SERVER['SCRIPT_NAME'])
       && stripos($_SERVER['SCRIPT_NAME'], 'plugins.php') !== false;
     $checker = $checker ?: $this->services_checker;
diff --git a/lib/Config/Migrator.php b/lib/Config/Migrator.php
index 8037b47612..a3c6a6843f 100644
--- a/lib/Config/Migrator.php
+++ b/lib/Config/Migrator.php
@@ -17,7 +17,7 @@ class Migrator {
   private $charset_collate;
   private $models;
 
-  function __construct() {
+  public function __construct() {
     $this->prefix = Env::$db_prefix;
     $this->charset_collate = Env::$db_charset_collate;
     $this->models = [
@@ -54,7 +54,7 @@ class Migrator {
     ];
   }
 
-  function up() {
+  public function up() {
     global $wpdb;
 
     $output = [];
@@ -65,7 +65,7 @@ class Migrator {
     return $output;
   }
 
-  function down() {
+  public function down() {
     global $wpdb;
 
     $_this = $this;
@@ -77,7 +77,7 @@ class Migrator {
     array_map($drop_table, $this->models);
   }
 
-  function segments() {
+  public function segments() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(90) NOT NULL,',
@@ -92,7 +92,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function settings() {
+  public function settings() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(50) NOT NULL,',
@@ -105,7 +105,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function customFields() {
+  public function customFields() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(90) NOT NULL,',
@@ -119,7 +119,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function scheduledTasks() {
+  public function scheduledTasks() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'type varchar(90) NULL DEFAULT NULL,',
@@ -140,7 +140,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statsNotifications() {
+  public function statsNotifications() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -154,7 +154,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function scheduledTaskSubscribers() {
+  public function scheduledTaskSubscribers() {
     $attributes = [
       'task_id int(11) unsigned NOT NULL,',
       'subscriber_id int(11) unsigned NOT NULL,',
@@ -169,7 +169,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function sendingQueues() {
+  public function sendingQueues() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'task_id int(11) unsigned NOT NULL,',
@@ -191,7 +191,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function subscribers() {
+  public function subscribers() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'wp_user_id bigint(20) NULL,',
@@ -224,7 +224,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function subscriberSegment() {
+  public function subscriberSegment() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'subscriber_id int(11) unsigned NOT NULL,',
@@ -239,7 +239,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function subscriberCustomField() {
+  public function subscriberCustomField() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'subscriber_id int(11) unsigned NOT NULL,',
@@ -253,7 +253,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function subscriberIps() {
+  public function subscriberIps() {
     $attributes = [
       'ip varchar(45) NOT NULL,',
       'created_at timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,',
@@ -263,7 +263,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletters() {
+  public function newsletters() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'hash varchar(150) NULL DEFAULT NULL,',
@@ -290,7 +290,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterTemplates() {
+  public function newsletterTemplates() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) NULL DEFAULT 0,',
@@ -307,7 +307,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterOptionFields() {
+  public function newsletterOptionFields() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(90) NOT NULL,',
@@ -320,7 +320,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterOption() {
+  public function newsletterOption() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -334,7 +334,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterSegment() {
+  public function newsletterSegment() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -347,7 +347,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterLinks() {
+  public function newsletterLinks() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -364,7 +364,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function newsletterPosts() {
+  public function newsletterPosts() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -377,7 +377,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function forms() {
+  public function forms() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(90) NOT NULL,', // should be null but db_delta can't handle this change
@@ -392,7 +392,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsNewsletters() {
+  public function statisticsNewsletters() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -406,7 +406,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsClicks() {
+  public function statisticsClicks() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -424,7 +424,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsOpens() {
+  public function statisticsOpens() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -441,7 +441,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsUnsubscribes() {
+  public function statisticsUnsubscribes() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -456,7 +456,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsForms() {
+  public function statisticsForms() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'form_id int(11) unsigned NOT NULL,',
@@ -468,7 +468,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function statisticsWoocommercePurchases() {
+  public function statisticsWoocommercePurchases() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'newsletter_id int(11) unsigned NOT NULL,',
@@ -489,7 +489,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function mappingToExternalEntities() {
+  public function mappingToExternalEntities() {
     $attributes = [
       'old_id int(11) unsigned NOT NULL,',
       'type varchar(50) NOT NULL,',
@@ -501,7 +501,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function log() {
+  public function log() {
     $attributes = [
       'id bigint(20) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(255),',
@@ -513,7 +513,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function userFlags() {
+  public function userFlags() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'user_id bigint(20) NOT NULL,',
@@ -527,7 +527,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function featureFlags() {
+  public function featureFlags() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'name varchar(100) NOT NULL,',
@@ -540,7 +540,7 @@ class Migrator {
     return $this->sqlify(__FUNCTION__, $attributes);
   }
 
-  function dynamicSegmentFilters() {
+  public function dynamicSegmentFilters() {
     $attributes = [
       'id int(11) unsigned NOT NULL AUTO_INCREMENT,',
       'segment_id int(11) unsigned NOT NULL,',
diff --git a/lib/Config/PersonalDataErasers.php b/lib/Config/PersonalDataErasers.php
index 4df4c39812..752dc94006 100644
--- a/lib/Config/PersonalDataErasers.php
+++ b/lib/Config/PersonalDataErasers.php
@@ -7,11 +7,11 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class PersonalDataErasers {
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addFilter('wp_privacy_personal_data_erasers', [$this, 'registerSubscriberEraser']);
   }
 
-  function registerSubscriberEraser($erasers) {
+  public function registerSubscriberEraser($erasers) {
     $erasers['mailpet-subscriber'] = [
       'eraser_friendly_name' => WPFunctions::get()->__('MailPoet Subscribers', 'mailpoet'),
       'callback' => [new SubscriberPersonalDataEraser(), 'erase'],
diff --git a/lib/Config/PersonalDataExporters.php b/lib/Config/PersonalDataExporters.php
index ff1f2792a8..a130d91302 100644
--- a/lib/Config/PersonalDataExporters.php
+++ b/lib/Config/PersonalDataExporters.php
@@ -10,14 +10,14 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class PersonalDataExporters {
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addFilter('wp_privacy_personal_data_exporters', [$this, 'registerSubscriberExporter']);
     WPFunctions::get()->addFilter('wp_privacy_personal_data_exporters', [$this, 'registerSegmentsExporter']);
     WPFunctions::get()->addFilter('wp_privacy_personal_data_exporters', [$this, 'registerNewslettersExporter']);
     WPFunctions::get()->addFilter('wp_privacy_personal_data_exporters', [$this, 'registerNewsletterClicksExporter']);
   }
 
-  function registerSegmentsExporter($exporters) {
+  public function registerSegmentsExporter($exporters) {
     $exporters[] = [
       'exporter_friendly_name' => WPFunctions::get()->__('MailPoet Lists', 'mailpoet'),
       'callback' => [new SegmentsExporter(), 'export'],
@@ -25,7 +25,7 @@ class PersonalDataExporters {
     return $exporters;
   }
 
-  function registerSubscriberExporter($exporters) {
+  public function registerSubscriberExporter($exporters) {
     $exporters[] = [
       'exporter_friendly_name' => WPFunctions::get()->__('MailPoet Subscriber Data', 'mailpoet'),
       'callback' => [new SubscriberExporter(), 'export'],
@@ -33,7 +33,7 @@ class PersonalDataExporters {
     return $exporters;
   }
 
-  function registerNewslettersExporter($exporters) {
+  public function registerNewslettersExporter($exporters) {
     $exporters[] = [
       'exporter_friendly_name' => WPFunctions::get()->__('MailPoet Emails', 'mailpoet'),
       'callback' => [new NewslettersExporter(), 'export'],
@@ -41,7 +41,7 @@ class PersonalDataExporters {
     return $exporters;
   }
 
-  function registerNewsletterClicksExporter($exporters) {
+  public function registerNewsletterClicksExporter($exporters) {
     $exporters[] = [
       'exporter_friendly_name' => WPFunctions::get()->__('MailPoet Email Clicks', 'mailpoet'),
       'callback' => [new NewsletterClicksExporter(), 'export'],
diff --git a/lib/Config/Populator.php b/lib/Config/Populator.php
index 95706f4fe7..130de44cab 100644
--- a/lib/Config/Populator.php
+++ b/lib/Config/Populator.php
@@ -50,7 +50,7 @@ class Populator {
   /** @var FeaturesController */
   private $flags_controller;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     WPFunctions $wp,
     Captcha $captcha,
@@ -145,7 +145,7 @@ class Populator {
     $this->flags_controller = $flags_controller;
   }
 
-  function up() {
+  public function up() {
     $localizer = new Localizer();
     $localizer->forceLoadWebsiteLocaleText();
 
diff --git a/lib/Config/PopulatorData/DefaultForm.php b/lib/Config/PopulatorData/DefaultForm.php
index 406a659d32..5832bdad19 100644
--- a/lib/Config/PopulatorData/DefaultForm.php
+++ b/lib/Config/PopulatorData/DefaultForm.php
@@ -11,7 +11,7 @@ class DefaultForm {
   /** @var Styles */
   private $form_styles;
 
-  function __construct(Styles $form_styles) {
+  public function __construct(Styles $form_styles) {
     $this->form_styles = $form_styles;
   }
 
diff --git a/lib/Config/PopulatorData/Templates/AppWelcome.php b/lib/Config/PopulatorData/Templates/AppWelcome.php
index 4ea388167c..5bd227d67e 100644
--- a/lib/Config/PopulatorData/Templates/AppWelcome.php
+++ b/lib/Config/PopulatorData/Templates/AppWelcome.php
@@ -9,12 +9,12 @@ class AppWelcome {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/app_welcome';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("App Welcome", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Avocado.php b/lib/Config/PopulatorData/Templates/Avocado.php
index 843ab8efd0..8a7372bc22 100644
--- a/lib/Config/PopulatorData/Templates/Avocado.php
+++ b/lib/Config/PopulatorData/Templates/Avocado.php
@@ -9,12 +9,12 @@ class Avocado {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/avocado';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Avocado", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Birds.php b/lib/Config/PopulatorData/Templates/Birds.php
index 9376a7768f..9a6656e6fe 100644
--- a/lib/Config/PopulatorData/Templates/Birds.php
+++ b/lib/Config/PopulatorData/Templates/Birds.php
@@ -7,12 +7,12 @@ class Birds {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/birds';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Birds", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php b/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
index 3c1ac7f04d..bacb927c81 100644
--- a/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
+++ b/lib/Config/PopulatorData/Templates/BookStoreWithCoupon.php
@@ -9,12 +9,12 @@ class BookStoreWithCoupon {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/book-store-with-coupon';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Book store (with coupon)", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/BrandingAgencyNews.php b/lib/Config/PopulatorData/Templates/BrandingAgencyNews.php
index d330fb03ac..8545444640 100644
--- a/lib/Config/PopulatorData/Templates/BrandingAgencyNews.php
+++ b/lib/Config/PopulatorData/Templates/BrandingAgencyNews.php
@@ -8,12 +8,12 @@ class BrandingAgencyNews {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/branding-agency-news';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Branding Agency News", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/BuddhistTemple.php b/lib/Config/PopulatorData/Templates/BuddhistTemple.php
index 924861cbd5..1b92e6b012 100644
--- a/lib/Config/PopulatorData/Templates/BuddhistTemple.php
+++ b/lib/Config/PopulatorData/Templates/BuddhistTemple.php
@@ -7,12 +7,12 @@ class BuddhistTemple {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/buddhist-temple';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Buddhist Temple", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Charity.php b/lib/Config/PopulatorData/Templates/Charity.php
index 8be259485e..eb1fbd7f24 100644
--- a/lib/Config/PopulatorData/Templates/Charity.php
+++ b/lib/Config/PopulatorData/Templates/Charity.php
@@ -9,12 +9,12 @@ class Charity {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/charity';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Charity", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/CityLocalNews.php b/lib/Config/PopulatorData/Templates/CityLocalNews.php
index 81309ce1ff..45feafd123 100755
--- a/lib/Config/PopulatorData/Templates/CityLocalNews.php
+++ b/lib/Config/PopulatorData/Templates/CityLocalNews.php
@@ -8,12 +8,12 @@ class CityLocalNews {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/city-local-news';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("City News", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/ClearNews.php b/lib/Config/PopulatorData/Templates/ClearNews.php
index b07003331a..b5419f950b 100644
--- a/lib/Config/PopulatorData/Templates/ClearNews.php
+++ b/lib/Config/PopulatorData/Templates/ClearNews.php
@@ -9,12 +9,12 @@ class ClearNews {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/clear-news';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Clear News", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Coffee.php b/lib/Config/PopulatorData/Templates/Coffee.php
index efebc147bc..ab98a31cfc 100644
--- a/lib/Config/PopulatorData/Templates/Coffee.php
+++ b/lib/Config/PopulatorData/Templates/Coffee.php
@@ -9,12 +9,12 @@ class Coffee {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/coffee';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Coffee", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/College.php b/lib/Config/PopulatorData/Templates/College.php
index a7b831c6ab..0007967fe0 100644
--- a/lib/Config/PopulatorData/Templates/College.php
+++ b/lib/Config/PopulatorData/Templates/College.php
@@ -8,12 +8,12 @@ class College {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/college';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("College", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/ComputerRepair.php b/lib/Config/PopulatorData/Templates/ComputerRepair.php
index cf671f0ede..dfe1cca572 100644
--- a/lib/Config/PopulatorData/Templates/ComputerRepair.php
+++ b/lib/Config/PopulatorData/Templates/ComputerRepair.php
@@ -8,12 +8,12 @@ class ComputerRepair {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/computer-repair';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Computer Repair", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/DogFood.php b/lib/Config/PopulatorData/Templates/DogFood.php
index 7e1c2d0d84..b9c29d2577 100644
--- a/lib/Config/PopulatorData/Templates/DogFood.php
+++ b/lib/Config/PopulatorData/Templates/DogFood.php
@@ -9,12 +9,12 @@ class DogFood {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/dog-food';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Dog Food", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Drone.php b/lib/Config/PopulatorData/Templates/Drone.php
index 40a0269ed0..2428bbd2b2 100644
--- a/lib/Config/PopulatorData/Templates/Drone.php
+++ b/lib/Config/PopulatorData/Templates/Drone.php
@@ -9,12 +9,12 @@ class Drone {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/drone';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Drone", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Engineering.php b/lib/Config/PopulatorData/Templates/Engineering.php
index 45473f06db..087b9f2fd4 100755
--- a/lib/Config/PopulatorData/Templates/Engineering.php
+++ b/lib/Config/PopulatorData/Templates/Engineering.php
@@ -8,12 +8,12 @@ class Engineering {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/engineering';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Engineering", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Faith.php b/lib/Config/PopulatorData/Templates/Faith.php
index be659c485d..44fcb30ffa 100644
--- a/lib/Config/PopulatorData/Templates/Faith.php
+++ b/lib/Config/PopulatorData/Templates/Faith.php
@@ -9,12 +9,12 @@ class Faith {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/faith';
      $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Faith", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FarmersMarket.php b/lib/Config/PopulatorData/Templates/FarmersMarket.php
index 17c9f67b00..07aa5653fd 100644
--- a/lib/Config/PopulatorData/Templates/FarmersMarket.php
+++ b/lib/Config/PopulatorData/Templates/FarmersMarket.php
@@ -8,12 +8,12 @@ class FarmersMarket {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/farmers-market';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Farmers Market", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FashionBlog.php b/lib/Config/PopulatorData/Templates/FashionBlog.php
index 06b9eb9330..34878d9e0a 100644
--- a/lib/Config/PopulatorData/Templates/FashionBlog.php
+++ b/lib/Config/PopulatorData/Templates/FashionBlog.php
@@ -7,12 +7,12 @@ class FashionBlog {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/fashion-blog';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Fashion Blog", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FashionBlogA.php b/lib/Config/PopulatorData/Templates/FashionBlogA.php
index 78f604ebfb..fc5fc14c5d 100644
--- a/lib/Config/PopulatorData/Templates/FashionBlogA.php
+++ b/lib/Config/PopulatorData/Templates/FashionBlogA.php
@@ -9,12 +9,12 @@ class FashionBlogA {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/fashion-blog-a';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Women Fashion Store", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FashionShop.php b/lib/Config/PopulatorData/Templates/FashionShop.php
index a92ece6978..14b1f3c567 100644
--- a/lib/Config/PopulatorData/Templates/FashionShop.php
+++ b/lib/Config/PopulatorData/Templates/FashionShop.php
@@ -9,12 +9,12 @@ class FashionShop {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/fashion-shop';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Kids Shop", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FashionStore.php b/lib/Config/PopulatorData/Templates/FashionStore.php
index 15da540bc7..598c037c1d 100644
--- a/lib/Config/PopulatorData/Templates/FashionStore.php
+++ b/lib/Config/PopulatorData/Templates/FashionStore.php
@@ -9,12 +9,12 @@ class FashionStore {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/fashion';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Fashion Store", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FestivalEvent.php b/lib/Config/PopulatorData/Templates/FestivalEvent.php
index f6a1795121..ce9962757f 100644
--- a/lib/Config/PopulatorData/Templates/FestivalEvent.php
+++ b/lib/Config/PopulatorData/Templates/FestivalEvent.php
@@ -9,12 +9,12 @@ class FestivalEvent {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/festival_event';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Festival Event", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Fitness.php b/lib/Config/PopulatorData/Templates/Fitness.php
index e4876f2e7f..203ab9ffcc 100644
--- a/lib/Config/PopulatorData/Templates/Fitness.php
+++ b/lib/Config/PopulatorData/Templates/Fitness.php
@@ -9,12 +9,12 @@ class Fitness {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/fitness';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Fitness", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php b/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
index 230c17854c..e61033ec43 100644
--- a/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
+++ b/lib/Config/PopulatorData/Templates/FlowersWithCoupon.php
@@ -9,12 +9,12 @@ class FlowersWithCoupon {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/flowers-with-coupon';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Flowers (with coupon)", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/FoodBox.php b/lib/Config/PopulatorData/Templates/FoodBox.php
index f5a268ccf6..0800b690de 100644
--- a/lib/Config/PopulatorData/Templates/FoodBox.php
+++ b/lib/Config/PopulatorData/Templates/FoodBox.php
@@ -9,12 +9,12 @@ class FoodBox {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/food_box';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Welcome to FoodBox", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/GiftWelcome.php b/lib/Config/PopulatorData/Templates/GiftWelcome.php
index 6e325be888..ad5686fc4e 100644
--- a/lib/Config/PopulatorData/Templates/GiftWelcome.php
+++ b/lib/Config/PopulatorData/Templates/GiftWelcome.php
@@ -9,12 +9,12 @@ class GiftWelcome {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/gift';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Gift Welcome", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Guitarist.php b/lib/Config/PopulatorData/Templates/Guitarist.php
index 0fc92a7ead..a9f306fdd6 100644
--- a/lib/Config/PopulatorData/Templates/Guitarist.php
+++ b/lib/Config/PopulatorData/Templates/Guitarist.php
@@ -7,12 +7,12 @@ class Guitarist {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/guitarist';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Guitarist", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/HealthyFoodBlog.php b/lib/Config/PopulatorData/Templates/HealthyFoodBlog.php
index b3f6657528..f2de9cac63 100644
--- a/lib/Config/PopulatorData/Templates/HealthyFoodBlog.php
+++ b/lib/Config/PopulatorData/Templates/HealthyFoodBlog.php
@@ -8,12 +8,12 @@ class HealthyFoodBlog {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/healthy-food-blog';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Healthy Food Blog", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Hotels.php b/lib/Config/PopulatorData/Templates/Hotels.php
index 1476c8a88f..bd173ebf52 100644
--- a/lib/Config/PopulatorData/Templates/Hotels.php
+++ b/lib/Config/PopulatorData/Templates/Hotels.php
@@ -9,12 +9,12 @@ class Hotels {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/hotels';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Hotels", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/IndustryConference.php b/lib/Config/PopulatorData/Templates/IndustryConference.php
index 5fef228e64..5ceacb61f1 100644
--- a/lib/Config/PopulatorData/Templates/IndustryConference.php
+++ b/lib/Config/PopulatorData/Templates/IndustryConference.php
@@ -9,12 +9,12 @@ class IndustryConference {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/industry-conference';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Industry Conference", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/JazzClub.php b/lib/Config/PopulatorData/Templates/JazzClub.php
index b5c5048ce3..71b54d7ccd 100644
--- a/lib/Config/PopulatorData/Templates/JazzClub.php
+++ b/lib/Config/PopulatorData/Templates/JazzClub.php
@@ -7,12 +7,12 @@ class JazzClub {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/jazz-club';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Jazz Club", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/KidsClothing.php b/lib/Config/PopulatorData/Templates/KidsClothing.php
index b73e29e15f..cbfbc6c008 100644
--- a/lib/Config/PopulatorData/Templates/KidsClothing.php
+++ b/lib/Config/PopulatorData/Templates/KidsClothing.php
@@ -9,12 +9,12 @@ class KidsClothing {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/kids-clothing';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Kids Clothing", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/LifestyleBlogA.php b/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
index 0620484c43..ea10170454 100644
--- a/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
+++ b/lib/Config/PopulatorData/Templates/LifestyleBlogA.php
@@ -9,12 +9,12 @@ class LifestyleBlogA {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/lifestyle-blog-a';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Makeup Blog", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/LifestyleBlogB.php b/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
index a65df660af..567710c1c5 100644
--- a/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
+++ b/lib/Config/PopulatorData/Templates/LifestyleBlogB.php
@@ -9,12 +9,12 @@ class LifestyleBlogB {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/lifestyle-blog-b';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Lifestyle Blog", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Minimal.php b/lib/Config/PopulatorData/Templates/Minimal.php
index db23e329ca..93e34b9814 100644
--- a/lib/Config/PopulatorData/Templates/Minimal.php
+++ b/lib/Config/PopulatorData/Templates/Minimal.php
@@ -9,12 +9,12 @@ class Minimal {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/minimal';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Minimal", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/ModularStyleStories.php b/lib/Config/PopulatorData/Templates/ModularStyleStories.php
index f8dbc451c1..03905a470a 100644
--- a/lib/Config/PopulatorData/Templates/ModularStyleStories.php
+++ b/lib/Config/PopulatorData/Templates/ModularStyleStories.php
@@ -9,12 +9,12 @@ class ModularStyleStories {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/modular-style-stories';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Modular Style Stories", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Mosque.php b/lib/Config/PopulatorData/Templates/Mosque.php
index 71978bc3ba..8ae351a647 100644
--- a/lib/Config/PopulatorData/Templates/Mosque.php
+++ b/lib/Config/PopulatorData/Templates/Mosque.php
@@ -7,12 +7,12 @@ class Mosque {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/mosque';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Mosque", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Motor.php b/lib/Config/PopulatorData/Templates/Motor.php
index 3bfd689042..7bcf8e00f1 100644
--- a/lib/Config/PopulatorData/Templates/Motor.php
+++ b/lib/Config/PopulatorData/Templates/Motor.php
@@ -7,12 +7,12 @@ class Motor {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/motor';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Motor", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Music.php b/lib/Config/PopulatorData/Templates/Music.php
index 2704287785..9467cf5a2c 100644
--- a/lib/Config/PopulatorData/Templates/Music.php
+++ b/lib/Config/PopulatorData/Templates/Music.php
@@ -8,12 +8,12 @@ class Music {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/music';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Music", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/NewsDay.php b/lib/Config/PopulatorData/Templates/NewsDay.php
index 775fe5ef0b..2a8a4f35bd 100644
--- a/lib/Config/PopulatorData/Templates/NewsDay.php
+++ b/lib/Config/PopulatorData/Templates/NewsDay.php
@@ -9,12 +9,12 @@ class NewsDay {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/news_day';
      $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("News Day", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
index 82f2be8fa6..db46ffb71b 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank121Column.php
@@ -11,14 +11,14 @@ class NewsletterBlank121Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-2-1-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Newsletter: Blank 1:2:1 Column", 'mailpoet'),
       'categories' => json_encode(['standard', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
index df5bfedc8f..9faba2e36b 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank12Column.php
@@ -11,14 +11,14 @@ class NewsletterBlank12Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-2-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Newsletter: Blank 1:2 Column", 'mailpoet'),
       'categories' => json_encode(['standard', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
index 73c490b781..09a91aceda 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank13Column.php
@@ -11,14 +11,14 @@ class NewsletterBlank13Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-3-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Newsletter: Blank 1:3 Column", 'mailpoet'),
       'categories' => json_encode(['standard', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php b/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
index 6790bd1efc..2d377a5f42 100644
--- a/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/NewsletterBlank1Column.php
@@ -11,14 +11,14 @@ class NewsletterBlank1Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newsletter-blank-1-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Newsletter: Blank 1 Column", 'mailpoet'),
       'categories' => json_encode(['standard', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/NewspaperTraditional.php b/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
index 04516ff263..ca94af31c7 100644
--- a/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
+++ b/lib/Config/PopulatorData/Templates/NewspaperTraditional.php
@@ -9,12 +9,12 @@ class NewspaperTraditional {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/newspaper-traditional';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Newspaper Traditional", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/NotSoMedium.php b/lib/Config/PopulatorData/Templates/NotSoMedium.php
index 99acf0ef6f..dd7e588a21 100644
--- a/lib/Config/PopulatorData/Templates/NotSoMedium.php
+++ b/lib/Config/PopulatorData/Templates/NotSoMedium.php
@@ -9,12 +9,12 @@ class NotSoMedium {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/not-so-medium';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("One Full Post In An Email", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Painter.php b/lib/Config/PopulatorData/Templates/Painter.php
index 57112e47b0..8460d228e3 100644
--- a/lib/Config/PopulatorData/Templates/Painter.php
+++ b/lib/Config/PopulatorData/Templates/Painter.php
@@ -7,12 +7,12 @@ class Painter {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/painter';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Painter", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Phone.php b/lib/Config/PopulatorData/Templates/Phone.php
index 2607480d47..827290aced 100644
--- a/lib/Config/PopulatorData/Templates/Phone.php
+++ b/lib/Config/PopulatorData/Templates/Phone.php
@@ -9,12 +9,12 @@ class Phone {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/phone';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("New Phone Purchase", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Photography.php b/lib/Config/PopulatorData/Templates/Photography.php
index eafffdbb45..347fdca900 100644
--- a/lib/Config/PopulatorData/Templates/Photography.php
+++ b/lib/Config/PopulatorData/Templates/Photography.php
@@ -7,12 +7,12 @@ class Photography {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/photography';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Photography", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/PieceOfCake.php b/lib/Config/PopulatorData/Templates/PieceOfCake.php
index aec7cdcebe..0d90f84532 100644
--- a/lib/Config/PopulatorData/Templates/PieceOfCake.php
+++ b/lib/Config/PopulatorData/Templates/PieceOfCake.php
@@ -9,12 +9,12 @@ class PieceOfCake {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/piece_of_cake';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Piece of cake", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Poet.php b/lib/Config/PopulatorData/Templates/Poet.php
index abe92a560e..4d975381c8 100644
--- a/lib/Config/PopulatorData/Templates/Poet.php
+++ b/lib/Config/PopulatorData/Templates/Poet.php
@@ -7,12 +7,12 @@ class Poet {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/poet';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Poet", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php b/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
index e06bd76c81..4dc1c43d02 100644
--- a/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/PostNotificationsBlank1Column.php
@@ -11,14 +11,14 @@ class PostNotificationsBlank1Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/post-notifications-blank-1-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Post Notifications: Blank 1 Column", 'mailpoet'),
       'categories' => json_encode(['notification', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/PrimarySchool.php b/lib/Config/PopulatorData/Templates/PrimarySchool.php
index e19492f951..4bc1a4ddec 100644
--- a/lib/Config/PopulatorData/Templates/PrimarySchool.php
+++ b/lib/Config/PopulatorData/Templates/PrimarySchool.php
@@ -8,12 +8,12 @@ class PrimarySchool {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/primary-school';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Primary School", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/RealEstate.php b/lib/Config/PopulatorData/Templates/RealEstate.php
index eefab97037..1657722d7e 100644
--- a/lib/Config/PopulatorData/Templates/RealEstate.php
+++ b/lib/Config/PopulatorData/Templates/RealEstate.php
@@ -9,12 +9,12 @@ class RealEstate {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/real-estate';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Real Estate", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/RenewableEnergy.php b/lib/Config/PopulatorData/Templates/RenewableEnergy.php
index f3454d9d7c..4565728c4c 100644
--- a/lib/Config/PopulatorData/Templates/RenewableEnergy.php
+++ b/lib/Config/PopulatorData/Templates/RenewableEnergy.php
@@ -8,12 +8,12 @@ class RenewableEnergy {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/renewable-energy';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Renewable Energy", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Retro.php b/lib/Config/PopulatorData/Templates/Retro.php
index 45f4203ed5..bf73f92d64 100644
--- a/lib/Config/PopulatorData/Templates/Retro.php
+++ b/lib/Config/PopulatorData/Templates/Retro.php
@@ -9,12 +9,12 @@ class Retro {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/retro';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Retro", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/RetroComputingMagazine.php b/lib/Config/PopulatorData/Templates/RetroComputingMagazine.php
index 01912f8f12..b1b90cc574 100644
--- a/lib/Config/PopulatorData/Templates/RetroComputingMagazine.php
+++ b/lib/Config/PopulatorData/Templates/RetroComputingMagazine.php
@@ -8,12 +8,12 @@ class RetroComputingMagazine {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/retro_computing_magazine';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Retro Computing Magazine", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/RockBand.php b/lib/Config/PopulatorData/Templates/RockBand.php
index 5974b6fdd1..6ad45a0b2d 100644
--- a/lib/Config/PopulatorData/Templates/RockBand.php
+++ b/lib/Config/PopulatorData/Templates/RockBand.php
@@ -7,12 +7,12 @@ class RockBand {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/rock-band';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Rock Band", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/RssSimpleNews.php b/lib/Config/PopulatorData/Templates/RssSimpleNews.php
index 9310d014f4..abc1788279 100644
--- a/lib/Config/PopulatorData/Templates/RssSimpleNews.php
+++ b/lib/Config/PopulatorData/Templates/RssSimpleNews.php
@@ -8,12 +8,12 @@ class RssSimpleNews {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/rss-simple-news';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Stripped RSS Style Layout", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/ScienceWeekly.php b/lib/Config/PopulatorData/Templates/ScienceWeekly.php
index a470c8bc41..5d1de575a4 100644
--- a/lib/Config/PopulatorData/Templates/ScienceWeekly.php
+++ b/lib/Config/PopulatorData/Templates/ScienceWeekly.php
@@ -8,12 +8,12 @@ class ScienceWeekly {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/science_weekly';
      $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Science Weekly", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Shoes.php b/lib/Config/PopulatorData/Templates/Shoes.php
index 91ec16daf6..c12a610904 100644
--- a/lib/Config/PopulatorData/Templates/Shoes.php
+++ b/lib/Config/PopulatorData/Templates/Shoes.php
@@ -8,12 +8,12 @@ class Shoes {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/shoes';
      $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Shoes", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/SimpleText.php b/lib/Config/PopulatorData/Templates/SimpleText.php
index 2c822e51d0..37867ad8f0 100644
--- a/lib/Config/PopulatorData/Templates/SimpleText.php
+++ b/lib/Config/PopulatorData/Templates/SimpleText.php
@@ -11,14 +11,14 @@ class SimpleText {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/simple-text';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Simple Text", 'mailpoet'),
       'categories' => json_encode(['standard', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/Software.php b/lib/Config/PopulatorData/Templates/Software.php
index f4d3eece40..5082990d8b 100644
--- a/lib/Config/PopulatorData/Templates/Software.php
+++ b/lib/Config/PopulatorData/Templates/Software.php
@@ -8,12 +8,12 @@ class Software {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/software';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Software", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Sunglasses.php b/lib/Config/PopulatorData/Templates/Sunglasses.php
index 15dabc6823..aa4b99b08d 100644
--- a/lib/Config/PopulatorData/Templates/Sunglasses.php
+++ b/lib/Config/PopulatorData/Templates/Sunglasses.php
@@ -8,12 +8,12 @@ class Sunglasses {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/sunglasses';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Sunglasses", 'mailpoet'),
       'categories' => json_encode(['welcome', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Synagogue.php b/lib/Config/PopulatorData/Templates/Synagogue.php
index 149e22bbe4..1b67b78532 100644
--- a/lib/Config/PopulatorData/Templates/Synagogue.php
+++ b/lib/Config/PopulatorData/Templates/Synagogue.php
@@ -7,12 +7,12 @@ class Synagogue {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/synagogue';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Synagogue", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/TakeAHike.php b/lib/Config/PopulatorData/Templates/TakeAHike.php
index 0d7c3d728e..41976287c1 100644
--- a/lib/Config/PopulatorData/Templates/TakeAHike.php
+++ b/lib/Config/PopulatorData/Templates/TakeAHike.php
@@ -8,12 +8,12 @@ class TakeAHike {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/take_a_hike';
      $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Take a Hike", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/Vlogger.php b/lib/Config/PopulatorData/Templates/Vlogger.php
index 4edfb9b4a2..5f529fd9e1 100644
--- a/lib/Config/PopulatorData/Templates/Vlogger.php
+++ b/lib/Config/PopulatorData/Templates/Vlogger.php
@@ -7,12 +7,12 @@ class Vlogger {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/vlogger';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => __("Vlogger", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php b/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
index 4d31a4a4c5..26d17082c9 100644
--- a/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
+++ b/lib/Config/PopulatorData/Templates/WelcomeBlank12Column.php
@@ -11,14 +11,14 @@ class WelcomeBlank12Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/welcome-email-blank-1-2-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Welcome Email: Blank 1:2 Column", 'mailpoet'),
       'categories' => json_encode(['welcome', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php b/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
index 44b8f14688..42a4902c8c 100644
--- a/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
+++ b/lib/Config/PopulatorData/Templates/WelcomeBlank1Column.php
@@ -11,14 +11,14 @@ class WelcomeBlank1Column {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->assets_url = $assets_url;
     $this->external_template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/welcome-email-blank-1-column';
     $this->template_image_url = $this->assets_url . '/img/blank_templates';
     $this->social_icon_url = $this->assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Welcome Email: Blank 1 Column", 'mailpoet'),
       'categories' => json_encode(['welcome', 'blank']),
diff --git a/lib/Config/PopulatorData/Templates/WideStoryLayout.php b/lib/Config/PopulatorData/Templates/WideStoryLayout.php
index 32bd3865a6..255e986f98 100644
--- a/lib/Config/PopulatorData/Templates/WideStoryLayout.php
+++ b/lib/Config/PopulatorData/Templates/WideStoryLayout.php
@@ -8,12 +8,12 @@ class WideStoryLayout {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/wide-story-layout';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Wide Story Layout", 'mailpoet'),
       'categories' => json_encode(['notification', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/WineCity.php b/lib/Config/PopulatorData/Templates/WineCity.php
index 76388b8c74..a8a60e53f7 100644
--- a/lib/Config/PopulatorData/Templates/WineCity.php
+++ b/lib/Config/PopulatorData/Templates/WineCity.php
@@ -8,12 +8,12 @@ class WineCity {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/wine-city';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Wine City (with coupon)", 'mailpoet'),
       'categories' => json_encode(['woocommerce', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/WordPressTheme.php b/lib/Config/PopulatorData/Templates/WordPressTheme.php
index 69c1b0a2a2..9eeeec7654 100755
--- a/lib/Config/PopulatorData/Templates/WordPressTheme.php
+++ b/lib/Config/PopulatorData/Templates/WordPressTheme.php
@@ -8,12 +8,12 @@ class WordPressTheme {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
     $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/word-press-theme';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("WordPress Theme", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/WorldCup.php b/lib/Config/PopulatorData/Templates/WorldCup.php
index b8a3b84fcb..1c3e58ad4d 100644
--- a/lib/Config/PopulatorData/Templates/WorldCup.php
+++ b/lib/Config/PopulatorData/Templates/WorldCup.php
@@ -8,12 +8,12 @@ class WorldCup {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/world_cup';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("World Cup", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PopulatorData/Templates/YogaStudio.php b/lib/Config/PopulatorData/Templates/YogaStudio.php
index 13f6f77fd2..d9a27f5b05 100644
--- a/lib/Config/PopulatorData/Templates/YogaStudio.php
+++ b/lib/Config/PopulatorData/Templates/YogaStudio.php
@@ -8,12 +8,12 @@ class YogaStudio {
   private $template_image_url;
   private $social_icon_url;
 
-  function __construct($assets_url) {
+  public function __construct($assets_url) {
      $this->template_image_url = 'https://ps.w.org/mailpoet/assets/newsletter-templates/yoga_studio';
     $this->social_icon_url = $assets_url . '/img/newsletter_editor/social-icons';
   }
 
-  function get() {
+  public function get() {
     return [
       'name' => WPFunctions::get()->__("Yoga Studio", 'mailpoet'),
       'categories' => json_encode(['standard', 'all']),
diff --git a/lib/Config/PrivacyPolicy.php b/lib/Config/PrivacyPolicy.php
index 6204924b9a..bbeca6ab92 100644
--- a/lib/Config/PrivacyPolicy.php
+++ b/lib/Config/PrivacyPolicy.php
@@ -8,13 +8,13 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class PrivacyPolicy {
 
-  function init() {
+  public function init() {
     if (function_exists('wp_add_privacy_policy_content')) {
       wp_add_privacy_policy_content(__('MailPoet', 'mailpoet'), $this->getPrivacyPolicyContent());
     }
   }
 
-  function getPrivacyPolicyContent() {
+  public function getPrivacyPolicyContent() {
     $content = (
       '<h2>' .
         WPFunctions::get()->__('MailPoet newsletter & emails', 'mailpoet') .
diff --git a/lib/Config/Renderer.php b/lib/Config/Renderer.php
index 5866b56919..5746818ba7 100644
--- a/lib/Config/Renderer.php
+++ b/lib/Config/Renderer.php
@@ -17,7 +17,7 @@ class Renderer {
   public $assets_manifest_js;
   public $assets_manifest_css;
 
-  function __construct($caching_enabled = false, $debugging_enabled = false) {
+  public function __construct($caching_enabled = false, $debugging_enabled = false) {
     $this->caching_enabled = $caching_enabled;
     $this->debugging_enabled = $debugging_enabled;
     $this->cache_path = Env::$cache_path;
@@ -46,35 +46,35 @@ class Renderer {
     $this->setupSyntax();
   }
 
-  function setupTranslations() {
+  public function setupTranslations() {
     $this->renderer->addExtension(new Twig\I18n(Env::$plugin_name));
   }
 
-  function setupFunctions() {
+  public function setupFunctions() {
     $this->renderer->addExtension(new Twig\Functions());
   }
 
-  function setupFilters() {
+  public function setupFilters() {
     $this->renderer->addExtension(new Twig\Filters());
   }
 
-  function setupHandlebars() {
+  public function setupHandlebars() {
     $this->renderer->addExtension(new Twig\Handlebars());
   }
 
-  function setupHelpscout() {
+  public function setupHelpscout() {
     $this->renderer->addExtension(new Twig\Helpscout());
   }
 
-  function setupAnalytics() {
+  public function setupAnalytics() {
     $this->renderer->addExtension(new Twig\Analytics());
   }
 
-  function setupPolls() {
+  public function setupPolls() {
     $this->renderer->addExtension(new Twig\Polls());
   }
 
-  function setupGlobalVariables() {
+  public function setupGlobalVariables() {
     $this->renderer->addExtension(new Twig\Assets([
       'version' => Env::$version,
       'base_url' => Env::$base_url,
@@ -84,7 +84,7 @@ class Renderer {
     ]));
   }
 
-  function setupSyntax() {
+  public function setupSyntax() {
     $lexer = new TwigLexer($this->renderer, [
       'tag_comment' => ['<#', '#>'],
       'tag_block' => ['<%', '%>'],
@@ -94,17 +94,17 @@ class Renderer {
     $this->renderer->setLexer($lexer);
   }
 
-  function detectCache() {
+  public function detectCache() {
     return $this->caching_enabled ? $this->cache_path : false;
   }
 
-  function setupDebug() {
+  public function setupDebug() {
     if ($this->debugging_enabled) {
       $this->renderer->addExtension(new DebugExtension());
     }
   }
 
-  function render($template, $context = []) {
+  public function render($template, $context = []) {
     try {
       return $this->renderer->render($template, $context);
     } catch (\RuntimeException $e) {
@@ -117,7 +117,7 @@ class Renderer {
     }
   }
 
-  function getAssetManifest($manifest_file) {
+  public function getAssetManifest($manifest_file) {
     if (is_readable($manifest_file)) {
       $contents = file_get_contents($manifest_file);
       if (is_string($contents)) {
@@ -127,13 +127,13 @@ class Renderer {
     return false;
   }
 
-  function getJsAsset($asset) {
+  public function getJsAsset($asset) {
     return (!empty($this->assets_manifest_js[$asset])) ?
       $this->assets_manifest_js[$asset] :
       $asset;
   }
 
-  function getCssAsset($asset) {
+  public function getCssAsset($asset) {
     return (!empty($this->assets_manifest_css[$asset])) ?
       $this->assets_manifest_css[$asset] :
       $asset;
diff --git a/lib/Config/RendererFactory.php b/lib/Config/RendererFactory.php
index 4b435e32bb..121d1cfa3f 100644
--- a/lib/Config/RendererFactory.php
+++ b/lib/Config/RendererFactory.php
@@ -7,7 +7,7 @@ class RendererFactory {
   /** @var Renderer|null */
   private $renderer;
 
-  function getRenderer() {
+  public function getRenderer() {
     if (!$this->renderer) {
       $caching = !WP_DEBUG;
       $debugging = WP_DEBUG;
diff --git a/lib/Config/RequirementsChecker.php b/lib/Config/RequirementsChecker.php
index bf6d324d93..5883bf6e2c 100644
--- a/lib/Config/RequirementsChecker.php
+++ b/lib/Config/RequirementsChecker.php
@@ -20,11 +20,11 @@ class RequirementsChecker {
     '\Html2Text\Html2Text',
   ];
 
-  function __construct($display_error_notice = true) {
+  public function __construct($display_error_notice = true) {
     $this->display_error_notice = $display_error_notice;
   }
 
-  function checkAllRequirements() {
+  public function checkAllRequirements() {
     $available_tests = [
       self::TEST_PDO_EXTENSION,
       self::TEST_FOLDER_PERMISSIONS,
@@ -42,7 +42,7 @@ class RequirementsChecker {
     return $results;
   }
 
-  function checkTempAndCacheFolderCreation() {
+  public function checkTempAndCacheFolderCreation() {
     $paths = [
       'temp_path' => Env::$temp_path,
       'cache_path' => Env::$cache_path,
@@ -67,7 +67,7 @@ class RequirementsChecker {
     return true;
   }
 
-  function checkPDOExtension() {
+  public function checkPDOExtension() {
     if (extension_loaded('pdo') && extension_loaded('pdo_mysql')) return true;
     $error = Helpers::replaceLinkTags(
       WPFunctions::get()->__('MailPoet requires a PDO_MYSQL PHP extension. Please read our [link]instructions[/link] on how to resolve this issue.', 'mailpoet'),
@@ -77,14 +77,14 @@ class RequirementsChecker {
     return $this->processError($error);
   }
 
-  function checkMbstringExtension() {
+  public function checkMbstringExtension() {
     if (!extension_loaded('mbstring')) {
       require_once Env::$util_path . '/Polyfills.php';
     }
     return true;
   }
 
-  function checkXmlExtension() {
+  public function checkXmlExtension() {
     if (extension_loaded('xml')) return true;
     $error = Helpers::replaceLinkTags(
       WPFunctions::get()->__('MailPoet requires an XML PHP extension. Please read our [link]instructions[/link] on how to resolve this issue.', 'mailpoet'),
@@ -94,7 +94,7 @@ class RequirementsChecker {
     return $this->processError($error);
   }
 
-  function checkVendorSource() {
+  public function checkVendorSource() {
     foreach ($this->vendor_classes as $dependency) {
       $dependency_path = $this->getDependencyPath($dependency);
       if (!$dependency_path) {
@@ -131,7 +131,7 @@ class RequirementsChecker {
     }
   }
 
-  function processError($error) {
+  public function processError($error) {
     if ($this->display_error_notice) {
       WPNotice::displayError($error);
     }
diff --git a/lib/Config/ServicesChecker.php b/lib/Config/ServicesChecker.php
index 0aa1f8e6e1..b58c26a386 100644
--- a/lib/Config/ServicesChecker.php
+++ b/lib/Config/ServicesChecker.php
@@ -20,7 +20,7 @@ class ServicesChecker {
     $this->settings = SettingsController::getInstance();
   }
 
-  function isMailPoetAPIKeyValid($display_error_notice = true, $force_check = false) {
+  public function isMailPoetAPIKeyValid($display_error_notice = true, $force_check = false) {
     if (!$force_check && !Bridge::isMPSendingServiceEnabled()) {
       return null;
     }
@@ -63,7 +63,7 @@ class ServicesChecker {
     return false;
   }
 
-  function isPremiumKeyValid($display_error_notice = true) {
+  public function isPremiumKeyValid($display_error_notice = true) {
     $premium_key_specified = Bridge::isPremiumKeySpecified();
     $premium_plugin_active = License::getLicense();
     $premium_key = $this->settings->get(Bridge::PREMIUM_KEY_STATE_SETTING_NAME);
diff --git a/lib/Config/Shortcodes.php b/lib/Config/Shortcodes.php
index 2b7804ea84..652533fc8f 100644
--- a/lib/Config/Shortcodes.php
+++ b/lib/Config/Shortcodes.php
@@ -17,12 +17,12 @@ class Shortcodes {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(Pages $subscription_pages, WPFunctions $wp) {
+  public function __construct(Pages $subscription_pages, WPFunctions $wp) {
     $this->subscription_pages = $subscription_pages;
     $this->wp = $wp;
   }
 
-  function init() {
+  public function init() {
     // form widget shortcode
     $this->wp->addShortcode('mailpoet_form', [$this, 'formWidget']);
 
@@ -51,7 +51,7 @@ class Shortcodes {
     $this->subscription_pages->initShortcodes();
   }
 
-  function formWidget($params = []) {
+  public function formWidget($params = []) {
     // IMPORTANT: fixes conflict with MagicMember
     $this->wp->removeShortcode('user_list');
 
@@ -64,7 +64,7 @@ class Shortcodes {
     }
   }
 
-  function getSubscribersCount($params) {
+  public function getSubscribersCount($params) {
     if (!empty($params['segments'])) {
       $segment_ids = array_map(function($segment_id) {
         return (int)trim($segment_id);
@@ -83,7 +83,7 @@ class Shortcodes {
     }
   }
 
-  function getArchive($params) {
+  public function getArchive($params) {
     $segment_ids = [];
     if (!empty($params['segments'])) {
       $segment_ids = array_map(function($segment_id) {
@@ -124,14 +124,14 @@ class Shortcodes {
     return $html;
   }
 
-  function renderArchiveDate($newsletter) {
+  public function renderArchiveDate($newsletter) {
     return $this->wp->dateI18n(
       $this->wp->getOption('date_format'),
       strtotime($newsletter->processed_at)
     );
   }
 
-  function renderArchiveSubject($newsletter, $subscriber, $queue) {
+  public function renderArchiveSubject($newsletter, $subscriber, $queue) {
     $preview_url = NewsletterUrl::getViewInBrowserUrl(
       NewsletterUrl::TYPE_ARCHIVE,
       $newsletter,
diff --git a/lib/Config/Updater.php b/lib/Config/Updater.php
index eb39e2bbee..24b391fe87 100644
--- a/lib/Config/Updater.php
+++ b/lib/Config/Updater.php
@@ -15,18 +15,18 @@ class Updater {
   /** @var SettingsController */
   private $settings;
 
-  function __construct($plugin_name, $slug, $version) {
+  public function __construct($plugin_name, $slug, $version) {
     $this->plugin = WPFunctions::get()->pluginBasename($plugin_name);
     $this->slug = $slug;
     $this->version = $version;
     $this->settings = SettingsController::getInstance();
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addFilter('pre_set_site_transient_update_plugins', [$this, 'checkForUpdate']);
   }
 
-  function checkForUpdate($update_transient) {
+  public function checkForUpdate($update_transient) {
     if (!$update_transient instanceof \stdClass) {
       $update_transient = new \stdClass;
     }
@@ -44,7 +44,7 @@ class Updater {
     return $update_transient;
   }
 
-  function getLatestVersion() {
+  public function getLatestVersion() {
     $key = $this->settings->get(Bridge::PREMIUM_KEY_SETTING_NAME);
     $api = new API($key);
     $data = $api->getPluginInformation($this->slug . '/latest');
diff --git a/lib/Cron/CronHelper.php b/lib/Cron/CronHelper.php
index a1698494dc..d06f0f1b84 100644
--- a/lib/Cron/CronHelper.php
+++ b/lib/Cron/CronHelper.php
@@ -29,18 +29,18 @@ class CronHelper {
     $this->wp = $wp;
   }
 
-  function getDaemonExecutionLimit() {
+  public function getDaemonExecutionLimit() {
     $limit = $this->wp->applyFilters('mailpoet_cron_get_execution_limit', self::DAEMON_EXECUTION_LIMIT);
     return $limit;
   }
 
-  function getDaemonExecutionTimeout() {
+  public function getDaemonExecutionTimeout() {
     $limit = $this->getDaemonExecutionLimit();
     $timeout = $limit * 1.75;
     return $this->wp->applyFilters('mailpoet_cron_get_execution_timeout', $timeout);
   }
 
-  function createDaemon($token) {
+  public function createDaemon($token) {
     $daemon = [
       'token' => $token,
       'status' => self::DAEMON_STATUS_ACTIVE,
@@ -54,15 +54,15 @@ class CronHelper {
     return $daemon;
   }
 
-  function restartDaemon($token) {
+  public function restartDaemon($token) {
     return $this->createDaemon($token);
   }
 
-  function getDaemon() {
+  public function getDaemon() {
     return $this->settings->fetch(self::DAEMON_SETTING);
   }
 
-  function saveDaemonLastError($error) {
+  public function saveDaemonLastError($error) {
     $daemon = $this->getDaemon();
     if ($daemon) {
       $daemon['last_error'] = $error;
@@ -71,7 +71,7 @@ class CronHelper {
     }
   }
 
-  function saveDaemonRunCompleted($run_completed_at) {
+  public function saveDaemonRunCompleted($run_completed_at) {
     $daemon = $this->getDaemon();
     if ($daemon) {
       $daemon['run_completed_at'] = $run_completed_at;
@@ -79,7 +79,7 @@ class CronHelper {
     }
   }
 
-  function saveDaemon($daemon) {
+  public function saveDaemon($daemon) {
     $daemon['updated_at'] = time();
     $this->settings->set(
       self::DAEMON_SETTING,
@@ -87,7 +87,7 @@ class CronHelper {
     );
   }
 
-  function deactivateDaemon($daemon) {
+  public function deactivateDaemon($daemon) {
     $daemon['status'] = self::DAEMON_STATUS_INACTIVE;
     $this->settings->set(
       self::DAEMON_SETTING,
@@ -95,11 +95,11 @@ class CronHelper {
     );
   }
 
-  function createToken() {
+  public function createToken() {
     return Security::generateRandomString();
   }
 
-  function pingDaemon() {
+  public function pingDaemon() {
     $url = $this->getCronUrl(
       CronDaemonEndpoint::ACTION_PING_RESPONSE
     );
@@ -112,11 +112,11 @@ class CronHelper {
     return $response;
   }
 
-  function validatePingResponse($response) {
+  public function validatePingResponse($response) {
     return $response === DaemonHttpRunner::PING_SUCCESS_RESPONSE;
   }
 
-  function accessDaemon($token) {
+  public function accessDaemon($token) {
     $data = ['token' => $token];
     $url = $this->getCronUrl(
       CronDaemonEndpoint::ACTION_RUN,
@@ -135,7 +135,7 @@ class CronHelper {
   /**
    * @return boolean|null
    */
-  function isDaemonAccessible() {
+  public function isDaemonAccessible() {
     $daemon = $this->getDaemon();
     if (!$daemon || !isset($daemon['run_accessed_at']) || $daemon['run_accessed_at'] === null) {
       return null;
@@ -152,7 +152,7 @@ class CronHelper {
     return null;
   }
 
-  function queryCronUrl($url) {
+  public function queryCronUrl($url) {
     $args = $this->wp->applyFilters(
       'mailpoet_cron_request_args',
       [
@@ -165,7 +165,7 @@ class CronHelper {
     return $this->wp->wpRemotePost($url, $args);
   }
 
-  function getCronUrl($action, $data = false) {
+  public function getCronUrl($action, $data = false) {
     $url = Router::buildRequest(
       CronDaemonEndpoint::ENDPOINT,
       $action,
@@ -177,7 +177,7 @@ class CronHelper {
       $custom_cron_url;
   }
 
-  function getSiteUrl($site_url = false) {
+  public function getSiteUrl($site_url = false) {
     // additional check for some sites running inside a virtual machine or behind
     // proxy where there could be different ports (e.g., host:8080 => guest:80)
     $site_url = ($site_url) ? $site_url : WPFunctions::get()->homeUrl();
@@ -200,7 +200,7 @@ class CronHelper {
     throw new \Exception(__('Site URL is unreachable.', 'mailpoet'));
   }
 
-  function enforceExecutionLimit($timer) {
+  public function enforceExecutionLimit($timer) {
     $elapsed_time = microtime(true) - $timer;
     if ($elapsed_time >= $this->getDaemonExecutionLimit()) {
       throw new \Exception(__('Maximum execution time has been reached.', 'mailpoet'), self::DAEMON_EXECUTION_LIMIT_REACHED);
diff --git a/lib/Cron/CronTrigger.php b/lib/Cron/CronTrigger.php
index 966de0d054..ae797db995 100644
--- a/lib/Cron/CronTrigger.php
+++ b/lib/Cron/CronTrigger.php
@@ -30,7 +30,7 @@ class CronTrigger {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(
+  public function __construct(
     MailPoet $mailpoet_trigger,
     WordPress $wordpress_trigger,
     SettingsController $settings
@@ -40,7 +40,7 @@ class CronTrigger {
     $this->settings = $settings;
   }
 
-  function init() {
+  public function init() {
     $current_method = $this->settings->get(self::SETTING_NAME . '.method');
     try {
       if ($current_method === self::METHOD_MAILPOET) {
diff --git a/lib/Cron/CronWorkerInterface.php b/lib/Cron/CronWorkerInterface.php
index ab4029aefe..741c22dc2c 100644
--- a/lib/Cron/CronWorkerInterface.php
+++ b/lib/Cron/CronWorkerInterface.php
@@ -6,33 +6,33 @@ use MailPoet\Models\ScheduledTask;
 
 interface CronWorkerInterface {
   /** @return string */
-  function getTaskType();
+  public function getTaskType();
 
   /** @return bool */
-  function scheduleAutomatically();
+  public function scheduleAutomatically();
 
   /** @return bool */
-  function supportsMultipleInstances();
+  public function supportsMultipleInstances();
 
   /** @return bool */
-  function checkProcessingRequirements();
+  public function checkProcessingRequirements();
 
-  function init();
+  public function init();
 
   /**
    * @param ScheduledTask $task
    * @param float $timer
    * @return bool
    */
-  function prepareTaskStrategy(ScheduledTask $task, $timer);
+  public function prepareTaskStrategy(ScheduledTask $task, $timer);
 
   /**
    * @param ScheduledTask $task
    * @param float $timer
    * @return bool
    */
-  function processTaskStrategy(ScheduledTask $task, $timer);
+  public function processTaskStrategy(ScheduledTask $task, $timer);
 
   /** @return \DateTimeInterface */
-  function getNextRunDate();
+  public function getNextRunDate();
 }
diff --git a/lib/Cron/CronWorkerRunner.php b/lib/Cron/CronWorkerRunner.php
index 050a1f8668..97f8924f12 100644
--- a/lib/Cron/CronWorkerRunner.php
+++ b/lib/Cron/CronWorkerRunner.php
@@ -23,14 +23,14 @@ class CronWorkerRunner {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(CronHelper $cron_helper, CronWorkerScheduler $cron_worker_scheduler, WPFunctions $wp) {
+  public function __construct(CronHelper $cron_helper, CronWorkerScheduler $cron_worker_scheduler, WPFunctions $wp) {
     $this->timer = microtime(true);
     $this->cron_helper = $cron_helper;
     $this->cron_worker_scheduler = $cron_worker_scheduler;
     $this->wp = $wp;
   }
 
-  function run(CronWorkerInterface $worker) {
+  public function run(CronWorkerInterface $worker) {
     // abort if execution limit is reached
     $this->cron_helper->enforceExecutionLimit($this->timer);
     $due_tasks = $this->getDueTasks($worker);
diff --git a/lib/Cron/CronWorkerScheduler.php b/lib/Cron/CronWorkerScheduler.php
index 9880f6a152..70507f3de9 100644
--- a/lib/Cron/CronWorkerScheduler.php
+++ b/lib/Cron/CronWorkerScheduler.php
@@ -10,11 +10,11 @@ class CronWorkerScheduler {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function schedule($task_type, $next_run_date) {
+  public function schedule($task_type, $next_run_date) {
     $already_scheduled = ScheduledTask::where('type', $task_type)
       ->whereNull('deleted_at')
       ->where('status', ScheduledTask::STATUS_SCHEDULED)
@@ -31,7 +31,7 @@ class CronWorkerScheduler {
     return $task;
   }
 
-  function reschedule(ScheduledTask $task, $timeout) {
+  public function reschedule(ScheduledTask $task, $timeout) {
     $scheduled_at = Carbon::createFromTimestamp($this->wp->currentTime('timestamp'));
     $task->scheduled_at = $scheduled_at->addMinutes($timeout);
     $task->setExpr('updated_at', 'NOW()');
diff --git a/lib/Cron/Daemon.php b/lib/Cron/Daemon.php
index 2b2c3cba6a..59c3a906d5 100644
--- a/lib/Cron/Daemon.php
+++ b/lib/Cron/Daemon.php
@@ -16,7 +16,7 @@ class Daemon {
   /** @var WorkersFactory */
   private $workers_factory;
 
-  function __construct(
+  public function __construct(
     CronHelper $cron_helper,
     CronWorkerRunner $cron_worker_runner,
     WorkersFactory $workers_factory
@@ -27,7 +27,7 @@ class Daemon {
     $this->cron_helper = $cron_helper;
   }
 
-  function run($settings_daemon_data) {
+  public function run($settings_daemon_data) {
     $settings_daemon_data['run_started_at'] = time();
     $this->cron_helper->saveDaemon($settings_daemon_data);
 
diff --git a/lib/Cron/DaemonHttpRunner.php b/lib/Cron/DaemonHttpRunner.php
index 5ecfaba223..aa86aee928 100644
--- a/lib/Cron/DaemonHttpRunner.php
+++ b/lib/Cron/DaemonHttpRunner.php
@@ -26,7 +26,7 @@ class DaemonHttpRunner {
   /** @var WordPress */
   private $wordpress_trigger;
 
-  function __construct(Daemon $daemon = null, CronHelper $cron_helper, SettingsController $settings, WordPress $wordpress_trigger) {
+  public function __construct(Daemon $daemon = null, CronHelper $cron_helper, SettingsController $settings, WordPress $wordpress_trigger) {
     $this->cron_helper = $cron_helper;
     $this->settings_daemon_data = $this->cron_helper->getDaemon();
     $this->token = $this->cron_helper->createToken();
@@ -36,7 +36,7 @@ class DaemonHttpRunner {
     $this->wordpress_trigger = $wordpress_trigger;
   }
 
-  function ping() {
+  public function ping() {
     // if Tracy enabled & called by 'MailPoet Cron' user agent, disable Tracy Bar
     // (happens in CronHelperTest because it's not a real integration test - calls other WP instance)
     $user_agent = isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : null;
@@ -47,7 +47,7 @@ class DaemonHttpRunner {
     $this->terminateRequest(self::PING_SUCCESS_RESPONSE);
   }
 
-  function run($request_data) {
+  public function run($request_data) {
     ignore_user_abort(true);
     if (strpos(@ini_get('disable_functions'), 'set_time_limit') === false) {
       set_time_limit(0);
@@ -94,33 +94,33 @@ class DaemonHttpRunner {
     return $this->callSelf();
   }
 
-  function pauseExecution($pause_time) {
+  public function pauseExecution($pause_time) {
     return sleep($pause_time);
   }
 
-  function callSelf() {
+  public function callSelf() {
     $this->cron_helper->accessDaemon($this->token);
     $this->terminateRequest();
   }
 
-  function abortWithError($message) {
+  public function abortWithError($message) {
     WPFunctions::get()->statusHeader(404, $message);
     exit;
   }
 
-  function terminateRequest($message = false) {
+  public function terminateRequest($message = false) {
     die($message);
   }
 
-  function isCronTriggerMethodWordPress() {
+  public function isCronTriggerMethodWordPress() {
     return $this->settings->get(CronTrigger::SETTING_NAME . '.method') === CronTrigger::METHOD_WORDPRESS;
   }
 
-  function checkWPTriggerExecutionRequirements() {
+  public function checkWPTriggerExecutionRequirements() {
     return $this->wordpress_trigger->checkExecutionRequirements();
   }
 
-  function stopCron() {
+  public function stopCron() {
     return $this->wordpress_trigger->stop();
   }
 
diff --git a/lib/Cron/Supervisor.php b/lib/Cron/Supervisor.php
index 871009347f..e5cf733ad9 100644
--- a/lib/Cron/Supervisor.php
+++ b/lib/Cron/Supervisor.php
@@ -9,16 +9,16 @@ class Supervisor {
   /** @var CronHelper */
   private $cron_helper;
 
-  function __construct(CronHelper $cron_helper) {
+  public function __construct(CronHelper $cron_helper) {
     $this->cron_helper = $cron_helper;
   }
 
-  function init() {
+  public function init() {
     $this->token = $this->cron_helper->createToken();
     $this->daemon = $this->getDaemon();
   }
 
-  function checkDaemon() {
+  public function checkDaemon() {
     $daemon = $this->daemon;
     $execution_timeout_exceeded =
       (time() - (int)$daemon['updated_at']) >= $this->cron_helper->getDaemonExecutionTimeout();
@@ -31,13 +31,13 @@ class Supervisor {
     return $daemon;
   }
 
-  function runDaemon() {
+  public function runDaemon() {
     $this->cron_helper->accessDaemon($this->token);
     $daemon = $this->cron_helper->getDaemon();
     return $daemon;
   }
 
-  function getDaemon() {
+  public function getDaemon() {
     $daemon = $this->cron_helper->getDaemon();
     if (!$daemon) {
       $this->cron_helper->createDaemon($this->token);
diff --git a/lib/Cron/Triggers/MailPoet.php b/lib/Cron/Triggers/MailPoet.php
index e8c99d9d08..df7a4117ff 100644
--- a/lib/Cron/Triggers/MailPoet.php
+++ b/lib/Cron/Triggers/MailPoet.php
@@ -8,11 +8,11 @@ class MailPoet {
   /** @var Supervisor */
   private $supervisor;
 
-  function __construct(Supervisor $supervisor) {
+  public function __construct(Supervisor $supervisor) {
     $this->supervisor = $supervisor;
   }
 
-  function run() {
+  public function run() {
     $this->supervisor->init();
     return $this->supervisor->checkDaemon();
   }
diff --git a/lib/Cron/Triggers/WordPress.php b/lib/Cron/Triggers/WordPress.php
index 6ab74fe8a0..75b9034f4a 100644
--- a/lib/Cron/Triggers/WordPress.php
+++ b/lib/Cron/Triggers/WordPress.php
@@ -45,7 +45,7 @@ class WordPress {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(
+  public function __construct(
     CronHelper $cron_helper,
     MailPoet $mailpoet_trigger,
     SettingsController $settings,
@@ -57,7 +57,7 @@ class WordPress {
     $this->cron_helper = $cron_helper;
   }
 
-  function run() {
+  public function run() {
     if (!$this->checkRunInterval()) {
       return false;
     }
@@ -77,12 +77,12 @@ class WordPress {
     return false;
   }
 
-  static function resetRunInterval() {
+  public static function resetRunInterval() {
     $settings = SettingsController::getInstance();
     $settings->set(self::LAST_RUN_AT_SETTING, 0);
   }
 
-  function checkExecutionRequirements() {
+  public function checkExecutionRequirements() {
     $this->loadTasksCounts();
 
     // migration
@@ -231,7 +231,7 @@ class WordPress {
     );
   }
 
-  function stop() {
+  public function stop() {
     $cron_daemon = $this->cron_helper->getDaemon();
     if ($cron_daemon) {
       $this->cron_helper->deactivateDaemon($cron_daemon);
diff --git a/lib/Cron/Workers/AuthorizedSendingEmailsCheck.php b/lib/Cron/Workers/AuthorizedSendingEmailsCheck.php
index 7be82b8afc..b7ea1df3d4 100644
--- a/lib/Cron/Workers/AuthorizedSendingEmailsCheck.php
+++ b/lib/Cron/Workers/AuthorizedSendingEmailsCheck.php
@@ -13,16 +13,16 @@ class AuthorizedSendingEmailsCheck extends SimpleWorker {
   /** @var AuthorizedEmailsController */
   private $authorized_emails_controller;
 
-  function __construct(AuthorizedEmailsController $authorized_emails_controller) {
+  public function __construct(AuthorizedEmailsController $authorized_emails_controller) {
     $this->authorized_emails_controller = $authorized_emails_controller;
     parent::__construct();
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return Bridge::isMPSendingServiceEnabled();
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $this->authorized_emails_controller->checkAuthorizedEmailAddresses();
     return true;
   }
diff --git a/lib/Cron/Workers/Beamer.php b/lib/Cron/Workers/Beamer.php
index cfbcbf3863..5c74ced243 100644
--- a/lib/Cron/Workers/Beamer.php
+++ b/lib/Cron/Workers/Beamer.php
@@ -18,17 +18,17 @@ class Beamer extends SimpleWorker {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     parent::__construct();
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     return $this->setLastAnnouncementDate();
   }
 
-  function setLastAnnouncementDate() {
+  public function setLastAnnouncementDate() {
     $response = $this->wp->wpRemoteGet(self::API_URL . '/posts?published=true&maxResults=1', [
       'headers' => [
         'Beamer-Api-Key' => self::API_KEY,
@@ -42,7 +42,7 @@ class Beamer extends SimpleWorker {
     return true;
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     $wp = new WPFunctions;
     $date = Carbon::createFromTimestamp($wp->currentTime('timestamp'));
     return $date->hour(11)->minute(00)->second(00)->addDay();
diff --git a/lib/Cron/Workers/Bounce.php b/lib/Cron/Workers/Bounce.php
index 21bbcba303..3abd960aee 100644
--- a/lib/Cron/Workers/Bounce.php
+++ b/lib/Cron/Workers/Bounce.php
@@ -29,22 +29,22 @@ class Bounce extends SimpleWorker {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(SettingsController $settings) {
+  public function __construct(SettingsController $settings) {
     $this->settings = $settings;
     parent::__construct();
   }
 
-  function init() {
+  public function init() {
     if (!$this->api) {
       $this->api = new API($this->settings->get(Mailer::MAILER_CONFIG_SETTING_NAME)['mailpoet_api_key']);
     }
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return Bridge::isMPSendingServiceEnabled();
   }
 
-  function prepareTaskStrategy(ScheduledTask $task, $timer) {
+  public function prepareTaskStrategy(ScheduledTask $task, $timer) {
     BounceTask::prepareSubscribers($task);
 
     if (!ScheduledTaskSubscriber::getUnprocessedCount($task->id)) {
@@ -54,7 +54,7 @@ class Bounce extends SimpleWorker {
     return true;
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $subscriber_batches = new BatchIterator($task->id, self::BATCH_SIZE);
 
     if (count($subscriber_batches) === 0) {
@@ -82,12 +82,12 @@ class Bounce extends SimpleWorker {
     return true;
   }
 
-  function processEmails(array $subscriber_emails) {
+  public function processEmails(array $subscriber_emails) {
     $checked_emails = $this->api->checkBounces($subscriber_emails);
     $this->processApiResponse((array)$checked_emails);
   }
 
-  function processApiResponse(array $checked_emails) {
+  public function processApiResponse(array $checked_emails) {
     foreach ($checked_emails as $email) {
       if (!isset($email['address'], $email['bounce'])) {
         continue;
diff --git a/lib/Cron/Workers/ExportFilesCleanup.php b/lib/Cron/Workers/ExportFilesCleanup.php
index 3a6da328f9..cd0b319320 100644
--- a/lib/Cron/Workers/ExportFilesCleanup.php
+++ b/lib/Cron/Workers/ExportFilesCleanup.php
@@ -10,7 +10,7 @@ class ExportFilesCleanup extends SimpleWorker {
   const TASK_TYPE = 'export_files_cleanup';
   const DELETE_FILES_AFTER_X_DAYS = 1;
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $iterator = new \GlobIterator(Export::getExportPath() . '/' . Export::getFilePrefix() . '*.*');
     foreach ($iterator as $file) {
       if (is_string($file)) {
diff --git a/lib/Cron/Workers/InactiveSubscribers.php b/lib/Cron/Workers/InactiveSubscribers.php
index f649bdf764..ac00af2671 100644
--- a/lib/Cron/Workers/InactiveSubscribers.php
+++ b/lib/Cron/Workers/InactiveSubscribers.php
@@ -19,7 +19,7 @@ class InactiveSubscribers extends SimpleWorker {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(
+  public function __construct(
     InactiveSubscribersController $inactive_subscribers_controller,
     SettingsController $settings
   ) {
@@ -29,7 +29,7 @@ class InactiveSubscribers extends SimpleWorker {
   }
 
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $tracking_enabled = (bool)$this->settings->get('tracking.enabled');
     if (!$tracking_enabled) {
       $this->schedule();
diff --git a/lib/Cron/Workers/KeyCheck/KeyCheckWorker.php b/lib/Cron/Workers/KeyCheck/KeyCheckWorker.php
index 82d88ea4ac..d74b152c19 100644
--- a/lib/Cron/Workers/KeyCheck/KeyCheckWorker.php
+++ b/lib/Cron/Workers/KeyCheck/KeyCheckWorker.php
@@ -9,13 +9,13 @@ use MailPoet\Services\Bridge;
 abstract class KeyCheckWorker extends SimpleWorker {
   public $bridge;
 
-  function init() {
+  public function init() {
     if (!$this->bridge) {
       $this->bridge = new Bridge();
     }
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     try {
       $result = $this->checkKey();
     } catch (\Exception $e) {
@@ -30,5 +30,5 @@ abstract class KeyCheckWorker extends SimpleWorker {
     return true;
   }
 
-  abstract function checkKey();
+  public abstract function checkKey();
 }
diff --git a/lib/Cron/Workers/KeyCheck/PremiumKeyCheck.php b/lib/Cron/Workers/KeyCheck/PremiumKeyCheck.php
index 4d1441a323..6bdacfd25d 100644
--- a/lib/Cron/Workers/KeyCheck/PremiumKeyCheck.php
+++ b/lib/Cron/Workers/KeyCheck/PremiumKeyCheck.php
@@ -11,17 +11,17 @@ class PremiumKeyCheck extends KeyCheckWorker {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(SettingsController $settings) {
+  public function __construct(SettingsController $settings) {
     $this->settings = $settings;
     parent::__construct();
   }
 
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return Bridge::isPremiumKeySpecified();
   }
 
-  function checkKey() {
+  public function checkKey() {
     $premium_key = $this->settings->get(Bridge::PREMIUM_KEY_SETTING_NAME);
     $result = $this->bridge->checkPremiumKey($premium_key);
     $this->bridge->storePremiumKeyAndState($premium_key, $result);
diff --git a/lib/Cron/Workers/KeyCheck/SendingServiceKeyCheck.php b/lib/Cron/Workers/KeyCheck/SendingServiceKeyCheck.php
index 68e2bd7f57..ee31fd30cb 100644
--- a/lib/Cron/Workers/KeyCheck/SendingServiceKeyCheck.php
+++ b/lib/Cron/Workers/KeyCheck/SendingServiceKeyCheck.php
@@ -12,16 +12,16 @@ class SendingServiceKeyCheck extends KeyCheckWorker {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(SettingsController $settings) {
+  public function __construct(SettingsController $settings) {
     $this->settings = $settings;
     parent::__construct();
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return Bridge::isMPSendingServiceEnabled();
   }
 
-  function checkKey() {
+  public function checkKey() {
     $mss_key = $this->settings->get(Mailer::MAILER_CONFIG_SETTING_NAME)['mailpoet_api_key'];
     $result = $this->bridge->checkMSSKey($mss_key);
     $this->bridge->storeMSSKeyAndState($mss_key, $result);
diff --git a/lib/Cron/Workers/Scheduler.php b/lib/Cron/Workers/Scheduler.php
index 81a18630bf..130e1e351f 100644
--- a/lib/Cron/Workers/Scheduler.php
+++ b/lib/Cron/Workers/Scheduler.php
@@ -29,7 +29,7 @@ class Scheduler {
   /** @var CronHelper */
   private $cron_helper;
 
-  function __construct(
+  public function __construct(
     SubscribersFinder $subscribers_finder,
     LoggerFactory $logger_factory,
     CronHelper $cron_helper
@@ -39,7 +39,7 @@ class Scheduler {
     $this->logger_factory = $logger_factory;
   }
 
-  function process($timer = false) {
+  public function process($timer = false) {
     $timer = $timer ?: microtime(true);
 
     // abort if execution limit is reached
@@ -67,7 +67,7 @@ class Scheduler {
     }
   }
 
-  function processWelcomeNewsletter($newsletter, $queue) {
+  public function processWelcomeNewsletter($newsletter, $queue) {
     $subscribers = $queue->getSubscribers();
     if (empty($subscribers[0])) {
       $queue->delete();
@@ -90,7 +90,7 @@ class Scheduler {
     return true;
   }
 
-  function processPostNotificationNewsletter($newsletter, $queue) {
+  public function processPostNotificationNewsletter($newsletter, $queue) {
     $this->logger_factory->getLogger(LoggerFactory::TOPIC_POST_NOTIFICATIONS)->addInfo(
       'process post notification in scheduler',
       ['newsletter_id' => $newsletter->id, 'task_id' => $queue->task_id]
@@ -135,7 +135,7 @@ class Scheduler {
     return true;
   }
 
-  function processScheduledAutomaticEmail($newsletter, $queue) {
+  public function processScheduledAutomaticEmail($newsletter, $queue) {
     if ($newsletter->sendTo === 'segment') {
       $segment = Segment::findOne($newsletter->segment);
       $result = $this->subscribers_finder->addSubscribersToTaskFromSegments($queue->task(), [$segment]);
@@ -159,7 +159,7 @@ class Scheduler {
     return true;
   }
 
-  function processScheduledStandardNewsletter($newsletter, SendingTask $task) {
+  public function processScheduledStandardNewsletter($newsletter, SendingTask $task) {
     $segments = $newsletter->segments()->findMany();
     $this->subscribers_finder->addSubscribersToTaskFromSegments($task->task(), $segments);
     // update current queue
@@ -172,7 +172,7 @@ class Scheduler {
     return true;
   }
 
-  function verifyMailpoetSubscriber($subscriber_id, $newsletter, $queue) {
+  public function verifyMailpoetSubscriber($subscriber_id, $newsletter, $queue) {
     $subscriber = Subscriber::findOne($subscriber_id);
     // check if subscriber is in proper segment
     $subscriber_in_segment =
@@ -187,7 +187,7 @@ class Scheduler {
     return $this->verifySubscriber($subscriber, $queue);
   }
 
-  function verifyWPSubscriber($subscriber_id, $newsletter, $queue) {
+  public function verifyWPSubscriber($subscriber_id, $newsletter, $queue) {
     // check if user has the proper role
     $subscriber = Subscriber::findOne($subscriber_id);
     if (!$subscriber || $subscriber->isWPUser() === false) {
@@ -204,7 +204,7 @@ class Scheduler {
     return $this->verifySubscriber($subscriber, $queue);
   }
 
-  function verifySubscriber($subscriber, $queue) {
+  public function verifySubscriber($subscriber, $queue) {
     if ($subscriber->status === Subscriber::STATUS_UNCONFIRMED) {
       // reschedule delivery
       $queue->rescheduleProgressively();
@@ -216,7 +216,7 @@ class Scheduler {
     return true;
   }
 
-  function deleteQueueOrUpdateNextRunDate($queue, $newsletter) {
+  public function deleteQueueOrUpdateNextRunDate($queue, $newsletter) {
     if ($newsletter->intervalType === PostNotificationScheduler::INTERVAL_IMMEDIATELY) {
       $queue->delete();
       return;
@@ -231,7 +231,7 @@ class Scheduler {
     }
   }
 
-  function createNotificationHistory($newsletter_id) {
+  public function createNotificationHistory($newsletter_id) {
     $newsletter = Newsletter::findOne($newsletter_id);
     $notification_history = $newsletter->createNotificationHistory();
     return ($notification_history->getErrors() === false) ?
@@ -258,7 +258,7 @@ class Scheduler {
     }
   }
 
-  static function getScheduledQueues() {
+  public static function getScheduledQueues() {
     return SendingTask::getScheduledQueues(self::TASK_BATCH_SIZE);
   }
 }
diff --git a/lib/Cron/Workers/SendingQueue/Migration.php b/lib/Cron/Workers/SendingQueue/Migration.php
index 123e6493f7..8957f33303 100644
--- a/lib/Cron/Workers/SendingQueue/Migration.php
+++ b/lib/Cron/Workers/SendingQueue/Migration.php
@@ -15,13 +15,13 @@ class Migration extends SimpleWorker {
   const TASK_TYPE = 'migration';
   const BATCH_SIZE = 20;
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     // if migration was completed, don't run it again
     $completed_tasks = $this->getCompletedTasks();
     return empty($completed_tasks);
   }
 
-  function prepareTaskStrategy(ScheduledTask $task, $timer) {
+  public function prepareTaskStrategy(ScheduledTask $task, $timer) {
     $unmigrated_columns = $this->checkUnmigratedColumnsExist();
     $unmigrated_queues_count = 0;
     $unmigrated_queue_subscribers = [];
@@ -48,7 +48,7 @@ class Migration extends SimpleWorker {
     return true;
   }
 
-  function pauseSending() {
+  public function pauseSending() {
     $mailer_log = MailerLog::getMailerLog();
     if (MailerLog::isSendingPaused($mailer_log)) {
       // sending is already paused
@@ -62,7 +62,7 @@ class Migration extends SimpleWorker {
     return MailerLog::pauseSending($mailer_log);
   }
 
-  function resumeSending() {
+  public function resumeSending() {
     $mailer_log = MailerLog::getMailerLog();
     if (!MailerLog::isSendingPaused($mailer_log)) {
       // sending is not paused
@@ -75,7 +75,7 @@ class Migration extends SimpleWorker {
     }
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $this->migrateSendingQueues($timer);
     $this->migrateSubscribers($timer);
     $this->resumeSending();
@@ -88,12 +88,12 @@ class Migration extends SimpleWorker {
     return in_array('type', $existing_columns);
   }
 
-  function getUnmigratedQueues() {
+  public function getUnmigratedQueues() {
     return SendingQueueModel::where('task_id', 0)
       ->whereNull('type');
   }
 
-  function getTaskIdsForUnmigratedSubscribers() {
+  public function getTaskIdsForUnmigratedSubscribers() {
     global $wpdb;
     $query = sprintf(
       'SELECT queues.`task_id` FROM %1$s queues INNER JOIN %2$s tasks ON queues.`task_id` = tasks.`id` ' .
@@ -110,7 +110,7 @@ class Migration extends SimpleWorker {
   /*
    * Migrate all sending queues without converting subscriber data
    */
-  function migrateSendingQueues($timer) {
+  public function migrateSendingQueues($timer) {
     global $wpdb;
 
     $queues = $this->getUnmigratedQueues()
@@ -160,7 +160,7 @@ class Migration extends SimpleWorker {
   /*
    * Migrate subscribers for in-progress sending tasks from the `subscribers` field to a separate table
    */
-  function migrateSubscribers($timer) {
+  public function migrateSubscribers($timer) {
     global $wpdb;
 
     // find in-progress queues that have serialized subscribers
@@ -188,7 +188,7 @@ class Migration extends SimpleWorker {
     return true;
   }
 
-  function migrateTaskSubscribers($task_id, $timer) {
+  public function migrateTaskSubscribers($task_id, $timer) {
     global $wpdb;
 
     $migrated_unprocessed_count = ScheduledTaskSubscriber::getUnprocessedCount($task_id);
@@ -241,7 +241,7 @@ class Migration extends SimpleWorker {
     return true;
   }
 
-  function getNextRunDate($wp = null) {
+  public function getNextRunDate($wp = null) {
     if (is_null($wp)) {
       $wp = new WPFunctions();
     }
diff --git a/lib/Cron/Workers/SendingQueue/SendingErrorHandler.php b/lib/Cron/Workers/SendingQueue/SendingErrorHandler.php
index af66a6edd1..a159bfbed4 100644
--- a/lib/Cron/Workers/SendingQueue/SendingErrorHandler.php
+++ b/lib/Cron/Workers/SendingQueue/SendingErrorHandler.php
@@ -7,7 +7,7 @@ use MailPoet\Mailer\MailerLog;
 use MailPoet\Tasks\Sending as SendingTask;
 
 class SendingErrorHandler {
-  function processError(
+  public function processError(
     MailerError $error,
     SendingTask $sending_task,
     array $prepared_subscribers_ids,
diff --git a/lib/Cron/Workers/SendingQueue/SendingQueue.php b/lib/Cron/Workers/SendingQueue/SendingQueue.php
index ec2dcd5719..ab9c6c12dd 100644
--- a/lib/Cron/Workers/SendingQueue/SendingQueue.php
+++ b/lib/Cron/Workers/SendingQueue/SendingQueue.php
@@ -47,7 +47,7 @@ class SendingQueue {
   /** @var CronHelper */
   private $cron_helper;
 
-  function __construct(
+  public function __construct(
     SendingErrorHandler $error_handler,
     StatsNotificationsScheduler $stats_notifications_scheduler,
     LoggerFactory $logger_factory,
@@ -68,7 +68,7 @@ class SendingQueue {
     $this->cron_helper = $cron_helper;
   }
 
-  function process($timer = false) {
+  public function process($timer = false) {
     $timer = $timer ?: microtime(true);
     $this->enforceSendingAndExecutionLimits($timer);
     foreach (self::getRunningQueues() as $queue) {
@@ -165,7 +165,7 @@ class SendingQueue {
     }
   }
 
-  function processQueue($queue, $newsletter, $subscribers, $timer) {
+  public function processQueue($queue, $newsletter, $subscribers, $timer) {
     // determine if processing is done in bulk or individually
     $processing_method = $this->mailer_task->getProcessingMethod();
     $prepared_newsletters = [];
@@ -227,7 +227,7 @@ class SendingQueue {
     return $queue;
   }
 
-  function sendNewsletter(
+  public function sendNewsletter(
     SendingTask $sending_task, $prepared_subscriber_id, $prepared_newsletter,
     $prepared_subscriber, $statistics, $timer, $extra_params = []
   ) {
@@ -247,7 +247,7 @@ class SendingQueue {
     );
   }
 
-  function sendNewsletters(
+  public function sendNewsletters(
     SendingTask $sending_task, $prepared_subscribers_ids, $prepared_newsletters,
     $prepared_subscribers, $statistics, $timer, $extra_params = []
   ) {
@@ -301,14 +301,14 @@ class SendingQueue {
     return $sending_task;
   }
 
-  function enforceSendingAndExecutionLimits($timer) {
+  public function enforceSendingAndExecutionLimits($timer) {
     // abort if execution limit is reached
     $this->cron_helper->enforceExecutionLimit($timer);
     // abort if sending limit has been reached
     MailerLog::enforceExecutionRequirements();
   }
 
-  static function getRunningQueues() {
+  public static function getRunningQueues() {
     return SendingTask::getRunningQueues(self::TASK_BATCH_SIZE);
   }
 }
diff --git a/lib/Cron/Workers/SendingQueue/Tasks/Links.php b/lib/Cron/Workers/SendingQueue/Tasks/Links.php
index aa4c7d3833..841239a7de 100644
--- a/lib/Cron/Workers/SendingQueue/Tasks/Links.php
+++ b/lib/Cron/Workers/SendingQueue/Tasks/Links.php
@@ -13,14 +13,14 @@ use MailPoet\Subscription\SubscriptionUrlFactory;
 use MailPoet\Util\Helpers;
 
 class Links {
-  static function process($rendered_newsletter, $newsletter, $queue) {
+  public static function process($rendered_newsletter, $newsletter, $queue) {
     list($rendered_newsletter, $links) =
       self::hashAndReplaceLinks($rendered_newsletter, $newsletter->id, $queue->id);
     self::saveLinks($links, $newsletter, $queue);
     return $rendered_newsletter;
   }
 
-  static function hashAndReplaceLinks($rendered_newsletter, $newsletter_id, $queue_id) {
+  public static function hashAndReplaceLinks($rendered_newsletter, $newsletter_id, $queue_id) {
     // join HTML and TEXT rendered body into a text string
     $content = Helpers::joinObject($rendered_newsletter);
     list($content, $links) = NewsletterLinks::process($content, $newsletter_id, $queue_id);
@@ -34,11 +34,11 @@ class Links {
     ];
   }
 
-  static function saveLinks($links, $newsletter, $queue) {
+  public static function saveLinks($links, $newsletter, $queue) {
     return NewsletterLinks::save($links, $newsletter->id, $queue->id);
   }
 
-  static function getUnsubscribeUrl($queue, $subscriber_id) {
+  public static function getUnsubscribeUrl($queue, $subscriber_id) {
     $subscriber = Subscriber::where('id', $subscriber_id)->findOne();
     $settings = SettingsController::getInstance();
     if ((boolean)$settings->get('tracking.enabled')) {
diff --git a/lib/Cron/Workers/SendingQueue/Tasks/Mailer.php b/lib/Cron/Workers/SendingQueue/Tasks/Mailer.php
index f9c37aa718..cc178d40c1 100644
--- a/lib/Cron/Workers/SendingQueue/Tasks/Mailer.php
+++ b/lib/Cron/Workers/SendingQueue/Tasks/Mailer.php
@@ -8,11 +8,11 @@ use MailPoet\Mailer\MailerLog;
 class Mailer {
   public $mailer;
 
-  function __construct($mailer = false) {
+  public function __construct($mailer = false) {
     $this->mailer = ($mailer) ? $mailer : $this->configureMailer();
   }
 
-  function configureMailer($newsletter = null) {
+  public function configureMailer($newsletter = null) {
     $sender['address'] = (!empty($newsletter->sender_address)) ?
       $newsletter->sender_address :
       false;
@@ -36,25 +36,25 @@ class Mailer {
     return $this->mailer;
   }
 
-  function getMailerLog() {
+  public function getMailerLog() {
     return MailerLog::getMailerLog();
   }
 
-  function updateSentCount() {
+  public function updateSentCount() {
     return MailerLog::incrementSentCount();
   }
 
-  function getProcessingMethod() {
+  public function getProcessingMethod() {
     return ($this->mailer->mailer_config['method'] === MailerFactory::METHOD_MAILPOET) ?
       'bulk' :
       'individual';
   }
 
-  function prepareSubscriberForSending($subscriber) {
+  public function prepareSubscriberForSending($subscriber) {
     return $this->mailer->formatSubscriberNameAndEmailAddress($subscriber);
   }
 
-  function sendBulk($prepared_newsletters, $prepared_subscribers, $extra_params = []) {
+  public function sendBulk($prepared_newsletters, $prepared_subscribers, $extra_params = []) {
     if ($this->getProcessingMethod() === 'individual') {
       throw new \LogicException('Trying to send a batch with individual processing method');
     }
@@ -65,7 +65,7 @@ class Mailer {
     );
   }
 
-  function send($prepared_newsletter, $prepared_subscriber, $extra_params = []) {
+  public function send($prepared_newsletter, $prepared_subscriber, $extra_params = []) {
     if ($this->getProcessingMethod() === 'bulk') {
       throw new \LogicException('Trying to send an individual email with a bulk processing method');
     }
diff --git a/lib/Cron/Workers/SendingQueue/Tasks/Newsletter.php b/lib/Cron/Workers/SendingQueue/Tasks/Newsletter.php
index 630c558147..7bf235c509 100644
--- a/lib/Cron/Workers/SendingQueue/Tasks/Newsletter.php
+++ b/lib/Cron/Workers/SendingQueue/Tasks/Newsletter.php
@@ -37,7 +37,7 @@ class Newsletter {
   /** @var Emoji */
   private $emoji;
 
-  function __construct(WPFunctions $wp = null, PostsTask $posts_task = null, GATracking $ga_tracking = null, Emoji $emoji = null) {
+  public function __construct(WPFunctions $wp = null, PostsTask $posts_task = null, GATracking $ga_tracking = null, Emoji $emoji = null) {
     $settings = SettingsController::getInstance();
     $this->tracking_enabled = (boolean)$settings->get('tracking.enabled');
     if ($wp === null) {
@@ -59,7 +59,7 @@ class Newsletter {
     $this->emoji = $emoji;
   }
 
-  function getNewsletterFromQueue($queue) {
+  public function getNewsletterFromQueue($queue) {
     // get existing active or sending newsletter
     $newsletter = $queue->newsletter()
       ->whereNull('deleted_at')
@@ -87,7 +87,7 @@ class Newsletter {
     return $newsletter;
   }
 
-  function preProcessNewsletter(\MailPoet\Models\Newsletter $newsletter, $sending_task) {
+  public function preProcessNewsletter(\MailPoet\Models\Newsletter $newsletter, $sending_task) {
     // return the newsletter if it was previously rendered
     if (!is_null($sending_task->getNewsletterRenderedBody())) {
       return (!$sending_task->validate()) ?
@@ -167,7 +167,7 @@ class Newsletter {
     return $newsletter;
   }
 
-  function prepareNewsletterForSending($newsletter, $subscriber, $queue) {
+  public function prepareNewsletterForSending($newsletter, $subscriber, $queue) {
     // shortcodes and links will be replaced in the subject, html and text body
     // to speed the processing, join content into a continuous string
     $rendered_newsletter = $queue->getNewsletterRenderedBody();
@@ -204,7 +204,7 @@ class Newsletter {
     ];
   }
 
-  function markNewsletterAsSent($newsletter, $queue) {
+  public function markNewsletterAsSent($newsletter, $queue) {
     // if it's a standard or notification history newsletter, update its status
     if ($newsletter->type === NewsletterModel::TYPE_STANDARD ||
        $newsletter->type === NewsletterModel::TYPE_NOTIFICATION_HISTORY
@@ -215,14 +215,14 @@ class Newsletter {
     }
   }
 
-  function getNewsletterSegments($newsletter) {
+  public function getNewsletterSegments($newsletter) {
     $segments = NewsletterSegmentModel::where('newsletter_id', $newsletter->id)
       ->select('segment_id')
       ->findArray();
     return Helpers::flattenArray($segments);
   }
 
-  function stopNewsletterPreProcessing($error_code = null) {
+  public function stopNewsletterPreProcessing($error_code = null) {
     MailerLog::processError(
       'queue_save',
       WPFunctions::get()->__('There was an error processing your newsletter during sending. If possible, please contact us and report this issue.', 'mailpoet'),
diff --git a/lib/Cron/Workers/SendingQueue/Tasks/Posts.php b/lib/Cron/Workers/SendingQueue/Tasks/Posts.php
index b50c4444fb..46e44a7793 100644
--- a/lib/Cron/Workers/SendingQueue/Tasks/Posts.php
+++ b/lib/Cron/Workers/SendingQueue/Tasks/Posts.php
@@ -14,7 +14,7 @@ class Posts {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function extractAndSave($rendered_newsletter, $newsletter) {
+  public function extractAndSave($rendered_newsletter, $newsletter) {
     if ($newsletter->type !== NewsletterModel::TYPE_NOTIFICATION_HISTORY) {
       return false;
     }
@@ -44,7 +44,7 @@ class Posts {
     return true;
   }
 
-  function getAlcPostsCount($rendered_newsletter, \MailPoet\Models\Newsletter $newsletter) {
+  public function getAlcPostsCount($rendered_newsletter, \MailPoet\Models\Newsletter $newsletter) {
     $template_posts_count = substr_count($newsletter->body, 'data-post-id');
     $newsletter_posts_count = substr_count($rendered_newsletter['html'], 'data-post-id');
     return $newsletter_posts_count - $template_posts_count;
diff --git a/lib/Cron/Workers/SendingQueue/Tasks/Shortcodes.php b/lib/Cron/Workers/SendingQueue/Tasks/Shortcodes.php
index 1f2c28cf08..3ba81967bc 100644
--- a/lib/Cron/Workers/SendingQueue/Tasks/Shortcodes.php
+++ b/lib/Cron/Workers/SendingQueue/Tasks/Shortcodes.php
@@ -5,7 +5,7 @@ namespace MailPoet\Cron\Workers\SendingQueue\Tasks;
 use MailPoet\Newsletter\Shortcodes\Shortcodes as NewsletterShortcodes;
 
 class Shortcodes {
-  static function process($content, $content_source = null, $newsletter = null, $subscriber = null, $queue = null) {
+  public static function process($content, $content_source = null, $newsletter = null, $subscriber = null, $queue = null) {
     $shortcodes = new NewsletterShortcodes($newsletter, $subscriber, $queue);
     return $shortcodes->replace($content, $content_source);
   }
diff --git a/lib/Cron/Workers/SimpleWorker.php b/lib/Cron/Workers/SimpleWorker.php
index 741eadbbea..c17bbd4de5 100644
--- a/lib/Cron/Workers/SimpleWorker.php
+++ b/lib/Cron/Workers/SimpleWorker.php
@@ -27,7 +27,7 @@ abstract class SimpleWorker implements CronWorkerInterface {
   /** @var CronWorkerScheduler */
   protected $cron_worker_scheduler;
 
-  function __construct() {
+  public function __construct() {
     if (static::TASK_TYPE === null) {
       throw new \Exception('Constant TASK_TYPE is not defined on subclass ' . get_class($this));
     }
@@ -37,34 +37,34 @@ abstract class SimpleWorker implements CronWorkerInterface {
     $this->cron_worker_scheduler = ContainerWrapper::getInstance()->get(CronWorkerScheduler::class);
   }
 
-  function getTaskType() {
+  public function getTaskType() {
     return static::TASK_TYPE;
   }
 
-  function supportsMultipleInstances() {
+  public function supportsMultipleInstances() {
     return static::SUPPORT_MULTIPLE_INSTANCES;
   }
 
-  function schedule() {
+  public function schedule() {
     $this->cron_worker_scheduler->schedule(static::TASK_TYPE, $this->getNextRunDate());
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return true;
   }
 
-  function init() {
+  public function init() {
   }
 
-  function prepareTaskStrategy(ScheduledTask $task, $timer) {
+  public function prepareTaskStrategy(ScheduledTask $task, $timer) {
     return true;
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     return true;
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     // random day of the next week
     $date = Carbon::createFromTimestamp($this->wp->currentTime('timestamp'));
     $date->setISODate((int)$date->format('o'), ((int)$date->format('W')) + 1, mt_rand(1, 7));
@@ -72,7 +72,7 @@ abstract class SimpleWorker implements CronWorkerInterface {
     return $date;
   }
 
-  function scheduleAutomatically() {
+  public function scheduleAutomatically() {
     return static::AUTOMATIC_SCHEDULING;
   }
 
diff --git a/lib/Cron/Workers/StatsNotifications/AutomatedEmails.php b/lib/Cron/Workers/StatsNotifications/AutomatedEmails.php
index 60f06ede4b..2e1c5b656c 100644
--- a/lib/Cron/Workers/StatsNotifications/AutomatedEmails.php
+++ b/lib/Cron/Workers/StatsNotifications/AutomatedEmails.php
@@ -37,7 +37,7 @@ class AutomatedEmails extends SimpleWorker {
   /** @var NewsletterStatisticsRepository */
   private $newsletter_statistics_repository;
 
-  function __construct(
+  public function __construct(
     Mailer $mailer,
     Renderer $renderer,
     SettingsController $settings,
@@ -54,7 +54,7 @@ class AutomatedEmails extends SimpleWorker {
     $this->newsletter_statistics_repository = $newsletter_statistics_repository;
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     $settings = $this->settings->get(Worker::SETTINGS_KEY);
     if (!is_array($settings)) {
       return false;
@@ -74,7 +74,7 @@ class AutomatedEmails extends SimpleWorker {
     return (bool)$settings['automated'];
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     try {
       $settings = $this->settings->get(Worker::SETTINGS_KEY);
       $newsletters = $this->getNewsletters();
@@ -147,7 +147,7 @@ class AutomatedEmails extends SimpleWorker {
     return $context;
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     $wp = new WPFunctions;
     $date = Carbon::createFromTimestamp($wp->currentTime('timestamp'));
     return $date->endOfMonth()->next(Carbon::MONDAY)->midDay();
diff --git a/lib/Cron/Workers/StatsNotifications/Scheduler.php b/lib/Cron/Workers/StatsNotifications/Scheduler.php
index 56b367effc..ad55e19bb1 100644
--- a/lib/Cron/Workers/StatsNotifications/Scheduler.php
+++ b/lib/Cron/Workers/StatsNotifications/Scheduler.php
@@ -31,7 +31,7 @@ class Scheduler {
   /** @var StatsNotificationsRepository */
   private $repository;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     EntityManager $entity_manager,
     StatsNotificationsRepository $repository
@@ -41,7 +41,7 @@ class Scheduler {
     $this->repository = $repository;
   }
 
-  function schedule(NewsletterEntity $newsletter) {
+  public function schedule(NewsletterEntity $newsletter) {
     if (!$this->shouldSchedule($newsletter)) {
       return false;
     }
diff --git a/lib/Cron/Workers/StatsNotifications/Worker.php b/lib/Cron/Workers/StatsNotifications/Worker.php
index 2d4a1dc905..e27ee6e557 100644
--- a/lib/Cron/Workers/StatsNotifications/Worker.php
+++ b/lib/Cron/Workers/StatsNotifications/Worker.php
@@ -60,7 +60,7 @@ class Worker {
   /** @var SubscribersRepository */
   private $subscribers_repository;
 
-  function __construct(
+  public function __construct(
     Mailer $mailer,
     Renderer $renderer,
     SettingsController $settings,
@@ -87,7 +87,7 @@ class Worker {
   }
 
   /** @throws \Exception */
-  function process($timer = false) {
+  public function process($timer = false) {
     $timer = $timer ?: microtime(true);
     $settings = $this->settings->get(self::SETTINGS_KEY);
     foreach ($this->repository->findScheduled(Sending::RESULT_BATCH_SIZE) as $stats_notification_entity) {
diff --git a/lib/Cron/Workers/SubscriberLinkTokens.php b/lib/Cron/Workers/SubscriberLinkTokens.php
index 8d8096f43d..0aca67f359 100644
--- a/lib/Cron/Workers/SubscriberLinkTokens.php
+++ b/lib/Cron/Workers/SubscriberLinkTokens.php
@@ -15,7 +15,7 @@ class SubscriberLinkTokens extends SimpleWorker {
   const BATCH_SIZE = 10000;
   const AUTOMATIC_SCHEDULING = false;
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $count = Subscriber::whereNull('link_token')->count();
     if ($count) {
       $auth_key = defined('AUTH_KEY') ? AUTH_KEY : '';
@@ -28,7 +28,7 @@ class SubscriberLinkTokens extends SimpleWorker {
     return true;
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     $wp = new WPFunctions();
     return Carbon::createFromTimestamp($wp->currentTime('timestamp'));
   }
diff --git a/lib/Cron/Workers/UnsubscribeTokens.php b/lib/Cron/Workers/UnsubscribeTokens.php
index a5e01274d1..94716eba4d 100644
--- a/lib/Cron/Workers/UnsubscribeTokens.php
+++ b/lib/Cron/Workers/UnsubscribeTokens.php
@@ -15,7 +15,7 @@ class UnsubscribeTokens extends SimpleWorker {
   const BATCH_SIZE = 1000;
   const AUTOMATIC_SCHEDULING = false;
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $meta = $task->getMeta();
     do {
       $this->cron_helper->enforceExecutionLimit($timer);
@@ -49,7 +49,7 @@ class UnsubscribeTokens extends SimpleWorker {
     return count($instances);
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     $wp = new WPFunctions;
     return Carbon::createFromTimestamp($wp->currentTime('timestamp'));
   }
diff --git a/lib/Cron/Workers/WooCommercePastOrders.php b/lib/Cron/Workers/WooCommercePastOrders.php
index 74bdf0d914..8945fae925 100644
--- a/lib/Cron/Workers/WooCommercePastOrders.php
+++ b/lib/Cron/Workers/WooCommercePastOrders.php
@@ -20,7 +20,7 @@ class WooCommercePastOrders extends SimpleWorker {
   /** @var WooCommercePurchases */
   private $woocommerce_purchases;
 
-  function __construct(
+  public function __construct(
     WCHelper $woocommerce_helper,
     WooCommercePurchases $woocommerce_purchases
   ) {
@@ -29,11 +29,11 @@ class WooCommercePastOrders extends SimpleWorker {
     parent::__construct();
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return $this->woocommerce_helper->isWooCommerceActive() && empty($this->getCompletedTasks()); // run only once
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $oldest_click = StatisticsClicks::orderByAsc('created_at')->limit(1)->findOne();
     if (!$oldest_click instanceof StatisticsClicks) {
       return true;
@@ -70,7 +70,7 @@ class WooCommercePastOrders extends SimpleWorker {
     return false;
   }
 
-  function getNextRunDate() {
+  public function getNextRunDate() {
     return Carbon::createFromTimestamp(WPFunctions::get()->currentTime('timestamp')); // schedule immediately
   }
 }
diff --git a/lib/Cron/Workers/WooCommerceSync.php b/lib/Cron/Workers/WooCommerceSync.php
index 2bc4521cf0..3da504f2ad 100644
--- a/lib/Cron/Workers/WooCommerceSync.php
+++ b/lib/Cron/Workers/WooCommerceSync.php
@@ -18,17 +18,17 @@ class WooCommerceSync extends SimpleWorker {
   /** @var WooCommerceHelper */
   private $woocommerce_helper;
 
-  function __construct(WooCommerceSegment $woocommerce_segment, WooCommerceHelper $woocommerce_helper) {
+  public function __construct(WooCommerceSegment $woocommerce_segment, WooCommerceHelper $woocommerce_helper) {
     $this->woocommerce_segment = $woocommerce_segment;
     $this->woocommerce_helper = $woocommerce_helper;
     parent::__construct();
   }
 
-  function checkProcessingRequirements() {
+  public function checkProcessingRequirements() {
     return $this->woocommerce_helper->isWooCommerceActive();
   }
 
-  function processTaskStrategy(ScheduledTask $task, $timer) {
+  public function processTaskStrategy(ScheduledTask $task, $timer) {
     $this->woocommerce_segment->synchronizeCustomers();
     return true;
   }
diff --git a/lib/Cron/Workers/WorkersFactory.php b/lib/Cron/Workers/WorkersFactory.php
index 33cbc12db3..af3b130e90 100644
--- a/lib/Cron/Workers/WorkersFactory.php
+++ b/lib/Cron/Workers/WorkersFactory.php
@@ -22,82 +22,82 @@ class WorkersFactory {
   }
 
   /** @return SchedulerWorker */
-  function createScheduleWorker() {
+  public function createScheduleWorker() {
     return $this->container->get(SchedulerWorker::class);
   }
 
   /** @return SendingQueueWorker */
-  function createQueueWorker() {
+  public function createQueueWorker() {
     return $this->container->get(SendingQueueWorker::class);
   }
 
   /** @return StatsNotificationsWorker */
-  function createStatsNotificationsWorker() {
+  public function createStatsNotificationsWorker() {
     return $this->container->get(StatsNotificationsWorker::class);
   }
 
   /** @return StatsNotificationsWorkerForAutomatedEmails */
-  function createStatsNotificationsWorkerForAutomatedEmails() {
+  public function createStatsNotificationsWorkerForAutomatedEmails() {
     return $this->container->get(StatsNotificationsWorkerForAutomatedEmails::class);
   }
 
   /** @return SendingServiceKeyCheckWorker */
-  function createSendingServiceKeyCheckWorker() {
+  public function createSendingServiceKeyCheckWorker() {
     return $this->container->get(SendingServiceKeyCheckWorker::class);
   }
 
   /** @return PremiumKeyCheckWorker */
-  function createPremiumKeyCheckWorker() {
+  public function createPremiumKeyCheckWorker() {
     return $this->container->get(PremiumKeyCheckWorker::class);
   }
 
   /** @return BounceWorker */
-  function createBounceWorker() {
+  public function createBounceWorker() {
     return $this->container->get(BounceWorker::class);
   }
 
   /** @return MigrationWorker */
-  function createMigrationWorker() {
+  public function createMigrationWorker() {
     return $this->container->get(MigrationWorker::class);
   }
 
   /** @return WooCommerceSyncWorker */
-  function createWooCommerceSyncWorker() {
+  public function createWooCommerceSyncWorker() {
     return $this->container->get(WooCommerceSyncWorker::class);
   }
 
   /** @return ExportFilesCleanup */
-  function createExportFilesCleanupWorker() {
+  public function createExportFilesCleanupWorker() {
     return $this->container->get(ExportFilesCleanup::class);
   }
 
   /** @return Beamer */
-  function createBeamerkWorker() {
+  public function createBeamerkWorker() {
     return $this->container->get(Beamer::class);
   }
 
   /** @return InactiveSubscribers */
-  function createInactiveSubscribersWorker() {
+  public function createInactiveSubscribersWorker() {
     return $this->container->get(InactiveSubscribers::class);
   }
 
   /** @return UnsubscribeTokens */
-  function createUnsubscribeTokensWorker() {
+  public function createUnsubscribeTokensWorker() {
     return $this->container->get(UnsubscribeTokens::class);
   }
 
   /** @return SubscriberLinkTokens */
-  function createSubscriberLinkTokensWorker() {
+  public function createSubscriberLinkTokensWorker() {
     return $this->container->get(SubscriberLinkTokens::class);
   }
 
   /** @return AuthorizedSendingEmailsCheck */
-  function createAuthorizedSendingEmailsCheckWorker() {
+  public function createAuthorizedSendingEmailsCheckWorker() {
     return $this->container->get(AuthorizedSendingEmailsCheck::class);
   }
 
   /** @return WooCommercePastOrders */
-  function createWooCommercePastOrdersWorker() {
+  public function createWooCommercePastOrdersWorker() {
     return $this->container->get(WooCommercePastOrders::class);
   }
 }
diff --git a/lib/CustomFields/ApiDataSanitizer.php b/lib/CustomFields/ApiDataSanitizer.php
index 5bc69c4856..98deaee492 100644
--- a/lib/CustomFields/ApiDataSanitizer.php
+++ b/lib/CustomFields/ApiDataSanitizer.php
@@ -18,7 +18,7 @@ class ApiDataSanitizer {
   const ERROR_NO_VALUES = 1009;
   const ERROR_NO_VALUE = 1010;
 
-  function sanitize(array $data = []) {
+  public function sanitize(array $data = []) {
     $this->checkMandatoryStringParameter($data, 'name');
     $this->checkMandatoryStringParameter($data, 'type');
     $this->checkParamsType($data);
diff --git a/lib/DI/ContainerConfigurator.php b/lib/DI/ContainerConfigurator.php
index fefc11f779..72a0a42ae0 100644
--- a/lib/DI/ContainerConfigurator.php
+++ b/lib/DI/ContainerConfigurator.php
@@ -8,15 +8,15 @@ use MailPoetVendor\Symfony\Component\DependencyInjection\Reference;
 
 class ContainerConfigurator implements IContainerConfigurator {
 
-  function getDumpNamespace() {
+  public function getDumpNamespace() {
     return 'MailPoetGenerated';
   }
 
-  function getDumpClassname() {
+  public function getDumpClassname() {
     return 'FreeCachedContainer';
   }
 
-  function configure(ContainerBuilder $container) {
+  public function configure(ContainerBuilder $container) {
     // Every service must be registered
     // Strict mode disables magical loading services by looking for an instance within other services
     // see https://symfonycasts.com/screencast/symfony4-upgrade/service-deprecations#strict-autowiring-mode
@@ -272,7 +272,7 @@ class ContainerConfigurator implements IContainerConfigurator {
       ]);
   }
 
-  static function getPremiumService($id, ContainerInterface $container = null) {
+  public static function getPremiumService($id, ContainerInterface $container = null) {
     if (!$container->has(IContainerConfigurator::PREMIUM_CONTAINER_SERVICE_SLUG)) {
       return null;
     }
diff --git a/lib/DI/ContainerFactory.php b/lib/DI/ContainerFactory.php
index d7edb9dbe7..396b23bea6 100644
--- a/lib/DI/ContainerFactory.php
+++ b/lib/DI/ContainerFactory.php
@@ -25,7 +25,7 @@ class ContainerFactory {
   /**
    * @return Container
    */
-  function getContainer() {
+  public function getContainer() {
     $dump_class = '\\' . $this->configurator->getDumpNamespace() . '\\' . $this->configurator->getDumpClassname();
     if (!$this->debug && class_exists($dump_class)) {
       $container = new $dump_class();
@@ -36,7 +36,7 @@ class ContainerFactory {
     return $container;
   }
 
-  function getConfiguredContainer() {
+  public function getConfiguredContainer() {
     return $this->configurator->configure(new ContainerBuilder());
   }
 }
diff --git a/lib/DI/ContainerWrapper.php b/lib/DI/ContainerWrapper.php
index 4a89145388..ab30731267 100644
--- a/lib/DI/ContainerWrapper.php
+++ b/lib/DI/ContainerWrapper.php
@@ -22,7 +22,7 @@ class ContainerWrapper implements ContainerInterface {
     $this->premium_container = $premium_container;
   }
 
-  function get($id) {
+  public function get($id) {
     try {
       return $this->free_container->get($id);
     } catch (NotFoundExceptionInterface $e) {
@@ -33,21 +33,21 @@ class ContainerWrapper implements ContainerInterface {
     }
   }
 
-  function has($id) {
+  public function has($id) {
     return $this->free_container->has($id) || ($this->premium_container && $this->premium_container->has($id));
   }
 
   /**
    * @return ContainerInterface|null
    */
-  function getPremiumContainer() {
+  public function getPremiumContainer() {
     if (!$this->premium_container && class_exists(\MailPoet\Premium\DI\ContainerConfigurator::class)) {
       $this->premium_container = self::createPremiumContainer($this->free_container);
     }
     return $this->premium_container;
   }
 
-  static function getInstance($debug = false) {
+  public static function getInstance($debug = false) {
     if (self::$instance) {
       return self::$instance;
     }
diff --git a/lib/DI/IContainerConfigurator.php b/lib/DI/IContainerConfigurator.php
index c28eada5ec..2218bc7035 100644
--- a/lib/DI/IContainerConfigurator.php
+++ b/lib/DI/IContainerConfigurator.php
@@ -8,7 +8,7 @@ interface IContainerConfigurator {
   const FREE_CONTAINER_SERVICE_SLUG = 'free_container';
   const PREMIUM_CONTAINER_SERVICE_SLUG = 'premium_container';
 
-  function configure(ContainerBuilder $container);
-  function getDumpNamespace();
-  function getDumpClassname();
+  public function configure(ContainerBuilder $container);
+  public function getDumpNamespace();
+  public function getDumpClassname();
 }
diff --git a/lib/Doctrine/Annotations/AnnotationReaderProvider.php b/lib/Doctrine/Annotations/AnnotationReaderProvider.php
index 4df19bb7cb..58a6ccfade 100644
--- a/lib/Doctrine/Annotations/AnnotationReaderProvider.php
+++ b/lib/Doctrine/Annotations/AnnotationReaderProvider.php
@@ -11,7 +11,7 @@ class AnnotationReaderProvider {
   /** @var CachedReader */
   private $annotation_reader;
 
-  function __construct() {
+  public function __construct() {
     // register annotation reader if doctrine/annotations package is installed
     // (i.e. in dev environment, on production metadata is dumped in the build)
     $read_annotations = class_exists(CachedReader::class) && class_exists(AnnotationReader::class);
@@ -24,7 +24,7 @@ class AnnotationReaderProvider {
   }
 
   /** @return CachedReader|null */
-  function getAnnotationReader() {
+  public function getAnnotationReader() {
     return $this->annotation_reader;
   }
 }
diff --git a/lib/Doctrine/ConfigurationFactory.php b/lib/Doctrine/ConfigurationFactory.php
index 1b5ebbdf2d..360a4bd648 100644
--- a/lib/Doctrine/ConfigurationFactory.php
+++ b/lib/Doctrine/ConfigurationFactory.php
@@ -22,12 +22,12 @@ class ConfigurationFactory {
   /** @var AnnotationReaderProvider */
   private $annotation_reader_provider;
 
-  function __construct($is_dev_mode = null, AnnotationReaderProvider $annotation_reader_provider) {
+  public function __construct($is_dev_mode = null, AnnotationReaderProvider $annotation_reader_provider) {
     $this->is_dev_mode = $is_dev_mode === null ? WP_DEBUG : $is_dev_mode;
     $this->annotation_reader_provider = $annotation_reader_provider;
   }
 
-  function createConfiguration() {
+  public function createConfiguration() {
     $configuration = new Configuration();
     $configuration->setNamingStrategy(new UnderscoreNamingStrategy());
 
diff --git a/lib/Doctrine/ConnectionFactory.php b/lib/Doctrine/ConnectionFactory.php
index cfd126b648..559c3a293d 100644
--- a/lib/Doctrine/ConnectionFactory.php
+++ b/lib/Doctrine/ConnectionFactory.php
@@ -21,7 +21,7 @@ class ConnectionFactory {
     JsonOrSerializedType::NAME => JsonOrSerializedType::class,
   ];
 
-  function createConnection() {
+  public function createConnection() {
     $platform_class = self::PLATFORM_CLASS;
     $connection_params = [
       'wrapperClass' => SerializableConnection::class,
diff --git a/lib/Doctrine/EntityManagerFactory.php b/lib/Doctrine/EntityManagerFactory.php
index 46d3b7e07a..7fb266728f 100644
--- a/lib/Doctrine/EntityManagerFactory.php
+++ b/lib/Doctrine/EntityManagerFactory.php
@@ -25,7 +25,7 @@ class EntityManagerFactory {
   /** @var ValidationListener */
   private $validation_listener;
 
-  function __construct(
+  public function __construct(
     Connection $connection,
     Configuration $configuration,
     TimestampListener $timestamp_listener,
@@ -37,7 +37,7 @@ class EntityManagerFactory {
     $this->validation_listener = $validation_listener;
   }
 
-  function createEntityManager() {
+  public function createEntityManager() {
     $entity_manager = EntityManager::create($this->connection, $this->configuration);
     $this->setupListeners($entity_manager);
     if (class_exists(Debugger::class)) {
diff --git a/lib/Doctrine/EntityTraits/DeletedAtTrait.php b/lib/Doctrine/EntityTraits/DeletedAtTrait.php
index 647293160d..8050fd51e1 100644
--- a/lib/Doctrine/EntityTraits/DeletedAtTrait.php
+++ b/lib/Doctrine/EntityTraits/DeletedAtTrait.php
@@ -13,12 +13,12 @@ trait DeletedAtTrait {
   private $deleted_at;
 
   /** @return DateTimeInterface|null */
-  function getDeletedAt() {
+  public function getDeletedAt() {
     return $this->deleted_at;
   }
 
   /** @param DateTimeInterface|null $deleted_at */
-  function setDeletedAt($deleted_at) {
+  public function setDeletedAt($deleted_at) {
     $this->deleted_at = $deleted_at;
   }
 }
diff --git a/lib/Doctrine/EventListeners/TimestampListener.php b/lib/Doctrine/EventListeners/TimestampListener.php
index cdd9a34129..dc8de761bf 100644
--- a/lib/Doctrine/EventListeners/TimestampListener.php
+++ b/lib/Doctrine/EventListeners/TimestampListener.php
@@ -13,11 +13,11 @@ class TimestampListener {
   /** @var Carbon */
   private $now;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->now = Carbon::createFromTimestamp($wp->currentTime('timestamp'));
   }
 
-  function prePersist(LifecycleEventArgs $event_args) {
+  public function prePersist(LifecycleEventArgs $event_args) {
     $entity = $event_args->getEntity();
     $entity_traits = $this->getEntityTraits($entity);
 
@@ -30,7 +30,7 @@ class TimestampListener {
     }
   }
 
-  function preUpdate(LifecycleEventArgs $event_args) {
+  public function preUpdate(LifecycleEventArgs $event_args) {
     $entity = $event_args->getEntity();
     $entity_traits = $this->getEntityTraits($entity);
 
diff --git a/lib/Doctrine/EventListeners/ValidationListener.php b/lib/Doctrine/EventListeners/ValidationListener.php
index 16cd9d250f..d5f3e1e541 100644
--- a/lib/Doctrine/EventListeners/ValidationListener.php
+++ b/lib/Doctrine/EventListeners/ValidationListener.php
@@ -10,11 +10,11 @@ class ValidationListener {
   /** @var ValidatorInterface */
   private $validator;
 
-  function __construct(ValidatorInterface $validator) {
+  public function __construct(ValidatorInterface $validator) {
     $this->validator = $validator;
   }
 
-  function onFlush(OnFlushEventArgs $event_args) {
+  public function onFlush(OnFlushEventArgs $event_args) {
     $unit_of_work = $event_args->getEntityManager()->getUnitOfWork();
 
     foreach ($unit_of_work->getScheduledEntityInsertions() as $entity) {
diff --git a/lib/Doctrine/MetadataCache.php b/lib/Doctrine/MetadataCache.php
index fe0cda7783..f51666f386 100644
--- a/lib/Doctrine/MetadataCache.php
+++ b/lib/Doctrine/MetadataCache.php
@@ -19,7 +19,7 @@ class MetadataCache extends CacheProvider {
   /** @var string */
   private $directory;
 
-  function __construct($dir, $is_read_only) {
+  public function __construct($dir, $is_read_only) {
     $this->is_dev_mode = defined('WP_DEBUG') && WP_DEBUG && !$is_read_only;
     $this->directory = rtrim($dir, '/\\');
     if (!file_exists($this->directory)) {
diff --git a/lib/Doctrine/Repository.php b/lib/Doctrine/Repository.php
index b4df9771b4..b5c05e1d88 100644
--- a/lib/Doctrine/Repository.php
+++ b/lib/Doctrine/Repository.php
@@ -17,7 +17,7 @@ abstract class Repository {
   /** @var DoctrineEntityRepository */
   protected $doctrine_repository;
 
-  function __construct(EntityManager $entity_manager) {
+  public function __construct(EntityManager $entity_manager) {
     $this->entity_manager = $entity_manager;
     $this->class_metadata = $entity_manager->getClassMetadata($this->getEntityClassName());
     $this->doctrine_repository = new DoctrineEntityRepository($this->entity_manager, $this->class_metadata);
@@ -30,7 +30,7 @@ abstract class Repository {
    * @param int|null $offset
    * @return array
    */
-  function findBy(array $criteria, array $order_by = null, $limit = null, $offset = null) {
+  public function findBy(array $criteria, array $order_by = null, $limit = null, $offset = null) {
     return $this->doctrine_repository->findBy($criteria, $order_by, $limit, $offset);
   }
 
@@ -39,7 +39,7 @@ abstract class Repository {
    * @param array|null $order_by
    * @return object|null
    */
-  function findOneBy(array $criteria, array $order_by = null) {
+  public function findOneBy(array $criteria, array $order_by = null) {
     return $this->doctrine_repository->findOneBy($criteria, $order_by);
   }
 
@@ -47,25 +47,25 @@ abstract class Repository {
    * @param mixed $id
    * @return object|null
    */
-  function findOneById($id) {
+  public function findOneById($id) {
     return $this->doctrine_repository->find($id);
   }
 
   /**
    * @return array
    */
-  function findAll() {
+  public function findAll() {
     return $this->doctrine_repository->findAll();
   }
 
   /**
    * @param object $entity
    */
-  function persist($entity) {
+  public function persist($entity) {
     $this->entity_manager->persist($entity);
   }
 
-  function truncate() {
+  public function truncate() {
     $cmd = $this->entity_manager->getClassMetadata($this->getEntityClassName());
     $table_name = $cmd->getTableName();
     $connection = $this->entity_manager->getConnection();
@@ -80,11 +80,11 @@ abstract class Repository {
   /**
    * @param object $entity
    */
-  function remove($entity) {
+  public function remove($entity) {
     $this->entity_manager->remove($entity);
   }
 
-  function flush() {
+  public function flush() {
     $this->entity_manager->flush();
   }
 
diff --git a/lib/Doctrine/SerializableConnection.php b/lib/Doctrine/SerializableConnection.php
index b0a49d0e27..5bc1366501 100644
--- a/lib/Doctrine/SerializableConnection.php
+++ b/lib/Doctrine/SerializableConnection.php
@@ -13,7 +13,7 @@ class SerializableConnection extends Connection {
   private $config;
   private $event_manager;
 
-  function __construct(array $params, Driver $driver, Configuration $config = null, EventManager $event_manager = null) {
+  public function __construct(array $params, Driver $driver, Configuration $config = null, EventManager $event_manager = null) {
     $this->params = $params;
     $this->driver = $driver;
     $this->config = $config;
@@ -21,11 +21,11 @@ class SerializableConnection extends Connection {
     parent::__construct($params, $driver, $config, $event_manager);
   }
 
-  function __sleep() {
+  public function __sleep() {
     return ['params', 'driver', 'config', 'event_manager'];
   }
 
-  function __wakeup() {
+  public function __wakeup() {
     parent::__construct($this->params, $this->driver, $this->config, $this->event_manager);
   }
 }
diff --git a/lib/Doctrine/TablePrefixMetadataFactory.php b/lib/Doctrine/TablePrefixMetadataFactory.php
index 3ccda7d043..051010e03d 100644
--- a/lib/Doctrine/TablePrefixMetadataFactory.php
+++ b/lib/Doctrine/TablePrefixMetadataFactory.php
@@ -17,14 +17,14 @@ class TablePrefixMetadataFactory extends ClassMetadataFactory {
   /** @var array */
   private $prefixed_map = [];
 
-  function __construct() {
+  public function __construct() {
     if (Env::$db_prefix === null) {
       throw new \RuntimeException('DB table prefix not initialized');
     }
     $this->prefix = Env::$db_prefix;
   }
 
-  function getMetadataFor($class_name) {
+  public function getMetadataFor($class_name) {
     $class_metadata = parent::getMetadataFor($class_name);
     if (isset($this->prefixed_map[$class_metadata->getName()])) {
       return $class_metadata;
@@ -40,7 +40,7 @@ class TablePrefixMetadataFactory extends ClassMetadataFactory {
     return $class_metadata;
   }
 
-  function addPrefix(ClassMetadata $class_metadata) {
+  public function addPrefix(ClassMetadata $class_metadata) {
     if (!$class_metadata->isInheritanceTypeSingleTable() || $class_metadata->getName() === $class_metadata->rootEntityName) {
       $class_metadata->setPrimaryTable([
         'name' => $this->prefix . $class_metadata->getTableName(),
diff --git a/lib/Doctrine/Types/JsonOrSerializedType.php b/lib/Doctrine/Types/JsonOrSerializedType.php
index 91294492a2..3c357f14b0 100644
--- a/lib/Doctrine/Types/JsonOrSerializedType.php
+++ b/lib/Doctrine/Types/JsonOrSerializedType.php
@@ -7,7 +7,7 @@ use MailPoetVendor\Doctrine\DBAL\Platforms\AbstractPlatform;
 class JsonOrSerializedType extends JsonType {
   const NAME = 'json_or_serialized';
 
-  function convertToPHPValue($value, AbstractPlatform $platform) {
+  public function convertToPHPValue($value, AbstractPlatform $platform) {
     if ($value === null) {
       return null;
     }
@@ -22,7 +22,7 @@ class JsonOrSerializedType extends JsonType {
     return parent::convertToPHPValue($value, $platform);
   }
 
-  function getName() {
+  public function getName() {
     return self::NAME;
   }
 }
diff --git a/lib/Doctrine/Types/JsonType.php b/lib/Doctrine/Types/JsonType.php
index 0aa560c7f1..b9386dacc5 100644
--- a/lib/Doctrine/Types/JsonType.php
+++ b/lib/Doctrine/Types/JsonType.php
@@ -8,11 +8,11 @@ use MailPoetVendor\Doctrine\DBAL\Types\Type;
 class JsonType extends Type {
   const NAME = 'json';
 
-  function getSQLDeclaration(array $fieldDeclaration, AbstractPlatform $platform) {
+  public function getSQLDeclaration(array $fieldDeclaration, AbstractPlatform $platform) {
     return $platform->getJsonTypeDeclarationSQL($fieldDeclaration);
   }
 
-  function convertToDatabaseValue($value, AbstractPlatform $platform) {
+  public function convertToDatabaseValue($value, AbstractPlatform $platform) {
     if ($value === null) {
       return null;
     }
@@ -27,7 +27,7 @@ class JsonType extends Type {
     return $encoded;
   }
 
-  function convertToPHPValue($value, AbstractPlatform $platform) {
+  public function convertToPHPValue($value, AbstractPlatform $platform) {
     if ($value === null || $value === '') {
       return null;
     }
@@ -41,11 +41,11 @@ class JsonType extends Type {
     return $decoded;
   }
 
-  function getName() {
+  public function getName() {
     return self::NAME;
   }
 
-  function requiresSQLCommentHint(AbstractPlatform $platform) {
+  public function requiresSQLCommentHint(AbstractPlatform $platform) {
     return !$platform->hasNativeJsonType();
   }
 
diff --git a/lib/Doctrine/Validator/ValidationException.php b/lib/Doctrine/Validator/ValidationException.php
index db1c33cfc9..5a7ca91a5e 100644
--- a/lib/Doctrine/Validator/ValidationException.php
+++ b/lib/Doctrine/Validator/ValidationException.php
@@ -12,7 +12,7 @@ class ValidationException extends \RuntimeException {
   /** @var ConstraintViolationListInterface|ConstraintViolationInterface[] */
   private $violations;
 
-  function __construct($resource_name, ConstraintViolationListInterface $violations) {
+  public function __construct($resource_name, ConstraintViolationListInterface $violations) {
     $this->resource_name = $resource_name;
     $this->violations = $violations;
 
@@ -23,17 +23,17 @@ class ValidationException extends \RuntimeException {
   }
 
   /** @return string */
-  function getResourceName() {
+  public function getResourceName() {
     return $this->resource_name;
   }
 
   /** @return ConstraintViolationListInterface|ConstraintViolationInterface[] */
-  function getViolations() {
+  public function getViolations() {
     return $this->violations;
   }
 
   /** @return string[] */
-  function getErrors() {
+  public function getErrors() {
     $messages = [];
     foreach ($this->violations as $violation) {
       $messages[] = $this->formatError($violation);
diff --git a/lib/Doctrine/Validator/ValidatorFactory.php b/lib/Doctrine/Validator/ValidatorFactory.php
index ec9b31e19d..f5559ba8da 100644
--- a/lib/Doctrine/Validator/ValidatorFactory.php
+++ b/lib/Doctrine/Validator/ValidatorFactory.php
@@ -13,11 +13,11 @@ class ValidatorFactory {
   /** @var AnnotationReaderProvider */
   private $annotation_reader_provider;
 
-  function __construct(AnnotationReaderProvider $annotation_reader_provider) {
+  public function __construct(AnnotationReaderProvider $annotation_reader_provider) {
     $this->annotation_reader_provider = $annotation_reader_provider;
   }
 
-  function createValidator() {
+  public function createValidator() {
     $builder = Validation::createValidatorBuilder();
 
     // annotation reader exists only in dev environment, on production cache is pre-generated
diff --git a/lib/DynamicSegments/DynamicSegmentHooks.php b/lib/DynamicSegments/DynamicSegmentHooks.php
index 7774eb6ac0..77d9f69b6f 100644
--- a/lib/DynamicSegments/DynamicSegmentHooks.php
+++ b/lib/DynamicSegments/DynamicSegmentHooks.php
@@ -18,11 +18,11 @@ class DynamicSegmentHooks {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function init() {
+  public function init() {
     $this->wp->addAction(
       'mailpoet_segments_with_subscriber_count',
       [$this, 'addSegmentsWithSubscribersCount']
@@ -54,32 +54,32 @@ class DynamicSegmentHooks {
     );
   }
 
-  function addSegmentsWithSubscribersCount($initial_segments) {
+  public function addSegmentsWithSubscribersCount($initial_segments) {
     $newsletters_add_segments = new AddToNewslettersSegments(new Loader(new DBMapper()), new SubscribersCount());
     return $newsletters_add_segments->add($initial_segments);
   }
 
-  function getSubscribersInSegmentsFinders(array $finders) {
+  public function getSubscribersInSegmentsFinders(array $finders) {
     $finders[] = new SendingNewslettersSubscribersFinder(new SingleSegmentLoader(new DBMapper()), new SubscribersIds());
     return $finders;
   }
 
-  function getSubscribersListingsInSegmentsHandlers(array $handlers) {
+  public function getSubscribersListingsInSegmentsHandlers(array $handlers) {
     $handlers[] = new SubscribersListingsHandlerFactory();
     return $handlers;
   }
 
-  function addDynamicFiltersToSubscribersListingsFilters($segment_filters) {
+  public function addDynamicFiltersToSubscribersListingsFilters($segment_filters) {
     $newsletters_add_segments = new AddToSubscribersFilters(new Loader(new DBMapper()), new SubscribersCount());
     return $newsletters_add_segments->add($segment_filters);
   }
 
-  function applySubscriberBulkAction(array $handlers) {
+  public function applySubscriberBulkAction(array $handlers) {
     $handlers[] = new SubscribersBulkActionHandler();
     return $handlers;
   }
 
-  function getSegmentFilters($segment_id) {
+  public function getSegmentFilters($segment_id) {
     $single_segment_loader = new SingleSegmentLoader(new DBMapper());
     return $single_segment_loader->load($segment_id)->getFilters();
   }
diff --git a/lib/DynamicSegments/Filters/EmailAction.php b/lib/DynamicSegments/Filters/EmailAction.php
index c5a7955faa..95e8fa40da 100644
--- a/lib/DynamicSegments/Filters/EmailAction.php
+++ b/lib/DynamicSegments/Filters/EmailAction.php
@@ -58,7 +58,7 @@ class EmailAction implements Filter {
     $this->action = $action;
   }
 
-  function toSql(ORM $orm) {
+  public function toSql(ORM $orm) {
     if (($this->action === EmailAction::ACTION_CLICKED) || ($this->action === EmailAction::ACTION_NOT_CLICKED)) {
       $table = StatisticsClicks::$_table;
     } else {
@@ -98,7 +98,7 @@ class EmailAction implements Filter {
     return $clause;
   }
 
-  function toArray() {
+  public function toArray() {
     return [
       'action' => $this->action,
       'newsletter_id' => $this->newsletter_id,
diff --git a/lib/DynamicSegments/Filters/Filter.php b/lib/DynamicSegments/Filters/Filter.php
index e0aae8ca12..5aa968990a 100644
--- a/lib/DynamicSegments/Filters/Filter.php
+++ b/lib/DynamicSegments/Filters/Filter.php
@@ -6,8 +6,8 @@ use MailPoetVendor\Idiorm\ORM;
 
 interface Filter {
 
-  function toSql(ORM $orm);
+  public function toSql(ORM $orm);
 
-  function toArray();
+  public function toArray();
 
 }
diff --git a/lib/DynamicSegments/Filters/UserRole.php b/lib/DynamicSegments/Filters/UserRole.php
index d27d091bc0..2e6a5b6629 100644
--- a/lib/DynamicSegments/Filters/UserRole.php
+++ b/lib/DynamicSegments/Filters/UserRole.php
@@ -23,7 +23,7 @@ class UserRole implements Filter {
     $this->connect = $connect;
   }
 
-  function toSql(ORM $orm) {
+  public function toSql(ORM $orm) {
     global $wpdb;
     $orm->join($wpdb->users, ['wpusers.id', '=', MP_SUBSCRIBERS_TABLE . '.wp_user_id'], 'wpusers')
       ->join($wpdb->usermeta, ['wpusers.ID',  '=', 'wpusermeta.user_id'], 'wpusermeta')
@@ -40,7 +40,7 @@ class UserRole implements Filter {
     ];
   }
 
-  function getRole() {
+  public function getRole() {
     return $this->role;
   }
 }
diff --git a/lib/DynamicSegments/Filters/WooCommerceCategory.php b/lib/DynamicSegments/Filters/WooCommerceCategory.php
index c0e7ca0001..c79a2df786 100644
--- a/lib/DynamicSegments/Filters/WooCommerceCategory.php
+++ b/lib/DynamicSegments/Filters/WooCommerceCategory.php
@@ -27,7 +27,7 @@ class WooCommerceCategory implements Filter {
     $this->connect = $connect;
   }
 
-  function toSql(ORM $orm) {
+  public function toSql(ORM $orm) {
     global $wpdb;
     $orm->distinct();
     $orm->rawJoin(
@@ -45,8 +45,8 @@ class WooCommerceCategory implements Filter {
     $orm->rawJoin(
       'INNER JOIN ' . $wpdb->term_taxonomy,
       '
-         term_taxonomy.term_taxonomy_id=term_relationships.term_taxonomy_id 
-         AND 
+         term_taxonomy.term_taxonomy_id=term_relationships.term_taxonomy_id
+         AND
          term_taxonomy.term_id IN (' . join(',', $this->getAllCategoryIds()) . ')',
       'term_taxonomy'
     );
@@ -64,7 +64,7 @@ class WooCommerceCategory implements Filter {
     return $ids;
   }
 
-  function toArray() {
+  public function toArray() {
     return [
       'action' => WooCommerceCategory::ACTION_CATEGORY,
       'category_id' => $this->category_id,
diff --git a/lib/DynamicSegments/Filters/WooCommerceProduct.php b/lib/DynamicSegments/Filters/WooCommerceProduct.php
index e496b1d507..e77058ab3f 100644
--- a/lib/DynamicSegments/Filters/WooCommerceProduct.php
+++ b/lib/DynamicSegments/Filters/WooCommerceProduct.php
@@ -26,7 +26,7 @@ class WooCommerceProduct implements Filter {
     $this->connect = $connect;
   }
 
-  function toSql(ORM $orm) {
+  public function toSql(ORM $orm) {
     global $wpdb;
     $orm->distinct();
     $orm->rawJoin(
@@ -37,8 +37,8 @@ class WooCommerceProduct implements Filter {
     $orm->join($wpdb->prefix . 'woocommerce_order_items', ['postmeta.post_id', '=', 'items.order_id'], 'items');
     $orm->rawJoin(
       'INNER JOIN ' . $wpdb->prefix . 'woocommerce_order_itemmeta',
-      "itemmeta.order_item_id=items.order_item_id 
-       AND itemmeta.meta_key='_product_id' 
+      "itemmeta.order_item_id=items.order_item_id
+       AND itemmeta.meta_key='_product_id'
        AND itemmeta.meta_value=" . $this->product_id,
       'itemmeta'
     );
@@ -46,7 +46,7 @@ class WooCommerceProduct implements Filter {
     return $orm;
   }
 
-  function toArray() {
+  public function toArray() {
     return [
       'action' => WooCommerceProduct::ACTION_PRODUCT,
       'product_id' => $this->product_id,
diff --git a/lib/DynamicSegments/FreePluginConnectors/AddToNewslettersSegments.php b/lib/DynamicSegments/FreePluginConnectors/AddToNewslettersSegments.php
index 960106d7be..d347bf90ab 100644
--- a/lib/DynamicSegments/FreePluginConnectors/AddToNewslettersSegments.php
+++ b/lib/DynamicSegments/FreePluginConnectors/AddToNewslettersSegments.php
@@ -23,7 +23,7 @@ class AddToNewslettersSegments {
    *
    * @return array
    */
-  function add(array $initial_segments) {
+  public function add(array $initial_segments) {
     $dynamic_segments = $this->getListings();
     return array_merge($initial_segments, $dynamic_segments);
   }
diff --git a/lib/DynamicSegments/FreePluginConnectors/AddToSubscribersFilters.php b/lib/DynamicSegments/FreePluginConnectors/AddToSubscribersFilters.php
index 85a763c3c8..6482185d5a 100644
--- a/lib/DynamicSegments/FreePluginConnectors/AddToSubscribersFilters.php
+++ b/lib/DynamicSegments/FreePluginConnectors/AddToSubscribersFilters.php
@@ -23,7 +23,7 @@ class AddToSubscribersFilters {
    *
    * @return array
    */
-  function add(array $segment_filters) {
+  public function add(array $segment_filters) {
     $dynamic_segments = $this->getListings();
     return $this->sort(array_merge($segment_filters, $dynamic_segments));
   }
diff --git a/lib/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinder.php b/lib/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinder.php
index aebd64f24e..f9d9d8abbb 100644
--- a/lib/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinder.php
+++ b/lib/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinder.php
@@ -27,7 +27,7 @@ class SendingNewslettersSubscribersFinder {
    *
    * @return Subscriber[]
    */
-  function findSubscribersInSegment(Segment $segment, array $subscribers_to_process_ids) {
+  public function findSubscribersInSegment(Segment $segment, array $subscribers_to_process_ids) {
     if ($segment->type !== DynamicSegment::TYPE_DYNAMIC) return [];
     $dynamic_segment = $this->single_segment_loader->load($segment->id);
     return $this->subscribers_ids_loader->load($dynamic_segment, $subscribers_to_process_ids);
@@ -38,7 +38,7 @@ class SendingNewslettersSubscribersFinder {
    *
    * @return array
    */
-  function getSubscriberIdsInSegment(Segment $segment) {
+  public function getSubscriberIdsInSegment(Segment $segment) {
     if ($segment->type !== DynamicSegment::TYPE_DYNAMIC) return [];
     $dynamic_segment = $this->single_segment_loader->load($segment->id);
     $result = $this->subscribers_ids_loader->load($dynamic_segment);
diff --git a/lib/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandler.php b/lib/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandler.php
index 1cf492805d..7ae442a25c 100644
--- a/lib/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandler.php
+++ b/lib/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandler.php
@@ -16,7 +16,7 @@ class SubscribersBulkActionHandler {
    * @return array
    * @throws \Exception
    */
-  function apply(array $segment, array $data) {
+  public function apply(array $segment, array $data) {
     if ($segment['type'] === DynamicSegment::TYPE_DYNAMIC) {
       $bulkAction = new BulkActionController(new BulkActionFactory(), new Handler());
       return $bulkAction->apply('\MailPoet\Models\SubscribersInDynamicSegment', $data);
diff --git a/lib/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactory.php b/lib/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactory.php
index c2f8f8adc5..100f9af7d6 100644
--- a/lib/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactory.php
+++ b/lib/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactory.php
@@ -8,7 +8,7 @@ use MailPoet\Models\Segment;
 
 class SubscribersListingsHandlerFactory {
 
-  function get(Segment $segment, $data) {
+  public function get(Segment $segment, $data) {
     if ($segment->type === DynamicSegment::TYPE_DYNAMIC) {
       $listing = new Handler();
       return $listing_data = $listing->get('\MailPoet\Models\SubscribersInDynamicSegment', $data);
diff --git a/lib/DynamicSegments/Mappers/DBMapper.php b/lib/DynamicSegments/Mappers/DBMapper.php
index c6401e1155..8d49e1a3ab 100644
--- a/lib/DynamicSegments/Mappers/DBMapper.php
+++ b/lib/DynamicSegments/Mappers/DBMapper.php
@@ -19,7 +19,7 @@ class DBMapper {
  *
  * @return DynamicSegment
  */
-  function mapSegment(DynamicSegment $segment_data, array $filters_data) {
+  public function mapSegment(DynamicSegment $segment_data, array $filters_data) {
     $filters = $this->getFilters($segment_data->id, $filters_data);
     $segment_data->setFilters($filters);
     return $segment_data;
@@ -31,7 +31,7 @@ class DBMapper {
    *
    * @return DynamicSegment[]
    */
-  function mapSegments(array $segments_data, array $filters_data) {
+  public function mapSegments(array $segments_data, array $filters_data) {
     $result = [];
     foreach ($segments_data as $segment_data) {
       $result[] = $this->mapSegment($segment_data, $filters_data);
diff --git a/lib/DynamicSegments/Mappers/FormDataMapper.php b/lib/DynamicSegments/Mappers/FormDataMapper.php
index 7bfd4be05a..1d92d2227f 100644
--- a/lib/DynamicSegments/Mappers/FormDataMapper.php
+++ b/lib/DynamicSegments/Mappers/FormDataMapper.php
@@ -18,7 +18,7 @@ class FormDataMapper {
    * @return DynamicSegment
    * @throws InvalidSegmentTypeException
    */
-  function mapDataToDB(array $data) {
+  public function mapDataToDB(array $data) {
     $filters = $this->getFilters($data);
     $dynamic_segment = $this->createDynamicSegment($data);
 
diff --git a/lib/DynamicSegments/Persistence/Loading/Loader.php b/lib/DynamicSegments/Persistence/Loading/Loader.php
index f434ce8df9..571e49a8de 100644
--- a/lib/DynamicSegments/Persistence/Loading/Loader.php
+++ b/lib/DynamicSegments/Persistence/Loading/Loader.php
@@ -18,7 +18,7 @@ class Loader {
   /**
    * @return DynamicSegment[]
    */
-  function load() {
+  public function load() {
     $segments = DynamicSegment::findAll();
     return $this->loadFilters($segments);
   }
diff --git a/lib/DynamicSegments/Persistence/Loading/SingleSegmentLoader.php b/lib/DynamicSegments/Persistence/Loading/SingleSegmentLoader.php
index 86fd693f4a..a30e2cb865 100644
--- a/lib/DynamicSegments/Persistence/Loading/SingleSegmentLoader.php
+++ b/lib/DynamicSegments/Persistence/Loading/SingleSegmentLoader.php
@@ -18,7 +18,7 @@ class SingleSegmentLoader {
    * @param string|int $segment_id
    * @return DynamicSegment
    */
-  function load($segment_id) {
+  public function load($segment_id) {
 
     $segment = DynamicSegment::findOne($segment_id);
     if (!$segment instanceof DynamicSegment) {
diff --git a/lib/DynamicSegments/Persistence/Loading/SubscribersCount.php b/lib/DynamicSegments/Persistence/Loading/SubscribersCount.php
index b9a2130f84..239ee51dcb 100644
--- a/lib/DynamicSegments/Persistence/Loading/SubscribersCount.php
+++ b/lib/DynamicSegments/Persistence/Loading/SubscribersCount.php
@@ -12,7 +12,7 @@ class SubscribersCount {
   /** @var RequirementsChecker */
   private $requirements_checker;
 
-  function __construct(RequirementsChecker $requirements_checker = null) {
+  public function __construct(RequirementsChecker $requirements_checker = null) {
     if (!$requirements_checker) {
       $requirements_checker = new RequirementsChecker(new WooCommerceHelper());
     }
@@ -24,7 +24,7 @@ class SubscribersCount {
    *
    * @return int
    */
-  function getSubscribersCount(DynamicSegment $dynamic_segment) {
+  public function getSubscribersCount(DynamicSegment $dynamic_segment) {
     $orm = Subscriber::selectExpr('count(distinct ' . Subscriber::$_table . '.id) as cnt');
     if ($this->requirements_checker->shouldSkipSegment($dynamic_segment)) {
       return 0;
diff --git a/lib/DynamicSegments/Persistence/Loading/SubscribersIds.php b/lib/DynamicSegments/Persistence/Loading/SubscribersIds.php
index 7b4e567f53..5b8c358e12 100644
--- a/lib/DynamicSegments/Persistence/Loading/SubscribersIds.php
+++ b/lib/DynamicSegments/Persistence/Loading/SubscribersIds.php
@@ -12,7 +12,7 @@ class SubscribersIds {
   /** @var RequirementsChecker */
   private $requirements_checker;
 
-  function __construct(RequirementsChecker $requirements_checker = null) {
+  public function __construct(RequirementsChecker $requirements_checker = null) {
     if (!$requirements_checker) {
       $requirements_checker = new RequirementsChecker(new WooCommerceHelper());
     }
@@ -27,7 +27,7 @@ class SubscribersIds {
    *
    * @return Subscriber[]
    */
-  function load(DynamicSegment $dynamic_segment, $limit_to_subscribers_ids = null) {
+  public function load(DynamicSegment $dynamic_segment, $limit_to_subscribers_ids = null) {
     $orm = Subscriber::selectExpr(Subscriber::$_table . '.id');
     if ($this->requirements_checker->shouldSkipSegment($dynamic_segment)) {
       return [];
diff --git a/lib/DynamicSegments/Persistence/Saver.php b/lib/DynamicSegments/Persistence/Saver.php
index ecb946a2a3..2deafe91a5 100644
--- a/lib/DynamicSegments/Persistence/Saver.php
+++ b/lib/DynamicSegments/Persistence/Saver.php
@@ -17,7 +17,7 @@ class Saver {
    * @return integer
    * @throws ErrorSavingException
    */
-  function save(DynamicSegment $segment) {
+  public function save(DynamicSegment $segment) {
     $db = ORM::get_db();
     $db->beginTransaction();
 
diff --git a/lib/DynamicSegments/RequirementsChecker.php b/lib/DynamicSegments/RequirementsChecker.php
index dfbfdb48c5..728dd99dfa 100644
--- a/lib/DynamicSegments/RequirementsChecker.php
+++ b/lib/DynamicSegments/RequirementsChecker.php
@@ -11,14 +11,14 @@ class RequirementsChecker {
   /** @var Helper */
   private $woocommerce_helper;
 
-  function __construct(Helper $woocommerce_helper = null) {
+  public function __construct(Helper $woocommerce_helper = null) {
     if (!$woocommerce_helper) {
       $woocommerce_helper = new Helper();
     }
     $this->woocommerce_helper = $woocommerce_helper;
   }
 
-  function shouldSkipSegment(DynamicSegment $segment) {
+  public function shouldSkipSegment(DynamicSegment $segment) {
     foreach ($segment->getFilters() as $filter) {
       if ($this->shouldSkipFilter($filter)) {
         return true;
diff --git a/lib/Entities/NewsletterEntity.php b/lib/Entities/NewsletterEntity.php
index 6dfce83d69..5ec9a4e4d8 100644
--- a/lib/Entities/NewsletterEntity.php
+++ b/lib/Entities/NewsletterEntity.php
@@ -143,7 +143,7 @@ class NewsletterEntity {
    */
   private $queues;
 
-  function __construct() {
+  public function __construct() {
     $this->newsletter_segments = new ArrayCollection();
     $this->options = new ArrayCollection();
     $this->queues = new ArrayCollection();
@@ -152,161 +152,161 @@ class NewsletterEntity {
   /**
    * @return string|null
    */
-  function getHash() {
+  public function getHash() {
     return $this->hash;
   }
 
   /**
    * @param string|null $hash
    */
-  function setHash($hash) {
+  public function setHash($hash) {
     $this->hash = $hash;
   }
 
   /**
    * @return string
    */
-  function getSubject() {
+  public function getSubject() {
     return $this->subject;
   }
 
   /**
    * @param string $subject
    */
-  function setSubject($subject) {
+  public function setSubject($subject) {
     $this->subject = $subject;
   }
 
   /**
    * @return string
    */
-  function getType() {
+  public function getType() {
     return $this->type;
   }
 
   /**
    * @param string $type
    */
-  function setType($type) {
+  public function setType($type) {
     $this->type = $type;
   }
 
   /**
    * @return string
    */
-  function getSenderAddress() {
+  public function getSenderAddress() {
     return $this->sender_address;
   }
 
   /**
    * @param string $sender_address
    */
-  function setSenderAddress($sender_address) {
+  public function setSenderAddress($sender_address) {
     $this->sender_address = $sender_address;
   }
 
   /**
    * @return string
    */
-  function getSenderName() {
+  public function getSenderName() {
     return $this->sender_name;
   }
 
   /**
    * @param string $sender_name
    */
-  function setSenderName($sender_name) {
+  public function setSenderName($sender_name) {
     $this->sender_name = $sender_name;
   }
 
   /**
    * @return string
    */
-  function getStatus() {
+  public function getStatus() {
     return $this->status;
   }
 
   /**
    * @param string $status
    */
-  function setStatus($status) {
+  public function setStatus($status) {
     $this->status = $status;
   }
 
   /**
    * @return string
    */
-  function getReplyToAddress() {
+  public function getReplyToAddress() {
     return $this->reply_to_address;
   }
 
   /**
    * @param string $reply_to_address
    */
-  function setReplyToAddress($reply_to_address) {
+  public function setReplyToAddress($reply_to_address) {
     $this->reply_to_address = $reply_to_address;
   }
 
   /**
    * @return string
    */
-  function getReplyToName() {
+  public function getReplyToName() {
     return $this->reply_to_name;
   }
 
   /**
    * @param string $reply_to_name
    */
-  function setReplyToName($reply_to_name) {
+  public function setReplyToName($reply_to_name) {
     $this->reply_to_name = $reply_to_name;
   }
 
   /**
    * @return string
    */
-  function getPreheader() {
+  public function getPreheader() {
     return $this->preheader;
   }
 
   /**
    * @param string $preheader
    */
-  function setPreheader($preheader) {
+  public function setPreheader($preheader) {
     $this->preheader = $preheader;
   }
 
   /**
    * @return array|null
    */
-  function getBody() {
+  public function getBody() {
     return $this->body;
   }
 
   /**
    * @param array|null $body
    */
-  function setBody($body) {
+  public function setBody($body) {
     $this->body = $body;
   }
 
   /**
    * @return DateTimeInterface|null
    */
-  function getSentAt() {
+  public function getSentAt() {
     return $this->sent_at;
   }
 
   /**
    * @param DateTimeInterface|null $sent_at
    */
-  function setSentAt($sent_at) {
+  public function setSentAt($sent_at) {
     $this->sent_at = $sent_at;
   }
 
   /**
    * @return string|null
    */
-  function getUnsubscribeToken() {
+  public function getUnsubscribeToken() {
     return $this->unsubscribe_token;
   }
 
@@ -328,14 +328,14 @@ class NewsletterEntity {
   /**
    * @param string|null $unsubscribe_token
    */
-  function setUnsubscribeToken($unsubscribe_token) {
+  public function setUnsubscribeToken($unsubscribe_token) {
     $this->unsubscribe_token = $unsubscribe_token;
   }
 
   /**
    * @return NewsletterEntity|null
    */
-  function getParent() {
+  public function getParent() {
     try {
       if ($this->parent && $this->parent->getId()) {
         return $this->parent;
@@ -349,35 +349,35 @@ class NewsletterEntity {
   /**
    * @param NewsletterEntity|null $parent
    */
-  function setParent($parent) {
+  public function setParent($parent) {
     $this->parent = $parent;
   }
 
   /**
    * @return NewsletterSegmentEntity[]|ArrayCollection
    */
-  function getNewsletterSegments() {
+  public function getNewsletterSegments() {
     return $this->newsletter_segments;
   }
 
   /**
    * @return NewsletterOptionEntity[]|ArrayCollection
    */
-  function getOptions() {
+  public function getOptions() {
     return $this->options;
   }
 
   /**
    * @return SendingQueueEntity[]|ArrayCollection
    */
-  function getQueues() {
+  public function getQueues() {
     return $this->queues;
   }
 
   /**
    * @return SendingQueueEntity|null
    */
-  function getLatestQueue() {
+  public function getLatestQueue() {
     $criteria = new Criteria();
     $criteria->orderBy(['id' => Criteria::DESC]);
     $criteria->setMaxResults(1);
diff --git a/lib/Entities/NewsletterLinkEntity.php b/lib/Entities/NewsletterLinkEntity.php
index 84498d3bca..ae91d8417d 100644
--- a/lib/Entities/NewsletterLinkEntity.php
+++ b/lib/Entities/NewsletterLinkEntity.php
@@ -83,7 +83,7 @@ class NewsletterLinkEntity {
   /**
    * @return int
    */
-  function getTotalClicksCount() {
+  public function getTotalClicksCount() {
     return $this->clicks->count();
   }
 }
diff --git a/lib/Entities/NewsletterOptionEntity.php b/lib/Entities/NewsletterOptionEntity.php
index 8f7dcdfb19..40c01f0730 100644
--- a/lib/Entities/NewsletterOptionEntity.php
+++ b/lib/Entities/NewsletterOptionEntity.php
@@ -37,42 +37,42 @@ class NewsletterOptionEntity {
   /**
    * @return string|null
    */
-  function getValue() {
+  public function getValue() {
     return $this->value;
   }
 
   /**
    * @param string|null $value
    */
-  function setValue($value) {
+  public function setValue($value) {
     $this->value = $value;
   }
 
   /**
    * @return NewsletterEntity
    */
-  function getNewsletter() {
+  public function getNewsletter() {
     return $this->newsletter;
   }
 
   /**
    * @param NewsletterEntity $newsletter
    */
-  function setNewsletter($newsletter) {
+  public function setNewsletter($newsletter) {
     $this->newsletter = $newsletter;
   }
 
   /**
    * @return NewsletterOptionFieldEntity
    */
-  function getOptionField() {
+  public function getOptionField() {
     return $this->option_field;
   }
 
   /**
    * @param NewsletterOptionFieldEntity $option_field
    */
-  function setOptionField($option_field) {
+  public function setOptionField($option_field) {
     $this->option_field = $option_field;
   }
 }
diff --git a/lib/Entities/NewsletterOptionFieldEntity.php b/lib/Entities/NewsletterOptionFieldEntity.php
index 7f11401add..ba86a8bbcf 100644
--- a/lib/Entities/NewsletterOptionFieldEntity.php
+++ b/lib/Entities/NewsletterOptionFieldEntity.php
@@ -34,28 +34,28 @@ class NewsletterOptionFieldEntity {
   /**
    * @return string
    */
-  function getName() {
+  public function getName() {
     return $this->name;
   }
 
   /**
    * @param string $name
    */
-  function setName($name) {
+  public function setName($name) {
     $this->name = $name;
   }
 
   /**
    * @return string
    */
-  function getNewsletterType() {
+  public function getNewsletterType() {
     return $this->newsletter_type;
   }
 
   /**
    * @param string $newsletter_type
    */
-  function setNewsletterType($newsletter_type) {
+  public function setNewsletterType($newsletter_type) {
     $this->newsletter_type = $newsletter_type;
   }
 }
diff --git a/lib/Entities/NewsletterSegmentEntity.php b/lib/Entities/NewsletterSegmentEntity.php
index ed8b48debb..a862b54a75 100644
--- a/lib/Entities/NewsletterSegmentEntity.php
+++ b/lib/Entities/NewsletterSegmentEntity.php
@@ -31,22 +31,22 @@ class NewsletterSegmentEntity {
   /**
    * @return NewsletterEntity
    */
-  function getNewsletter() {
+  public function getNewsletter() {
     return $this->newsletter;
   }
 
-  function setNewsletter(NewsletterEntity $newsletter) {
+  public function setNewsletter(NewsletterEntity $newsletter) {
     $this->newsletter = $newsletter;
   }
 
   /**
    * @return SegmentEntity
    */
-  function getSegment() {
+  public function getSegment() {
     return $this->segment;
   }
 
-  function setSegment(SegmentEntity $segment) {
+  public function setSegment(SegmentEntity $segment) {
     $this->segment = $segment;
   }
 }
diff --git a/lib/Entities/ScheduledTaskEntity.php b/lib/Entities/ScheduledTaskEntity.php
index 612849f538..21cc929d9c 100644
--- a/lib/Entities/ScheduledTaskEntity.php
+++ b/lib/Entities/ScheduledTaskEntity.php
@@ -66,84 +66,84 @@ class ScheduledTaskEntity {
   /**
    * @return string|null
    */
-  function getType() {
+  public function getType() {
     return $this->type;
   }
 
   /**
    * @param string|null $type
    */
-  function setType($type) {
+  public function setType($type) {
     $this->type = $type;
   }
 
   /**
    * @return string|null
    */
-  function getStatus() {
+  public function getStatus() {
     return $this->status;
   }
 
   /**
    * @param string|null $status
    */
-  function setStatus($status) {
+  public function setStatus($status) {
     $this->status = $status;
   }
 
   /**
    * @return int
    */
-  function getPriority() {
+  public function getPriority() {
     return $this->priority;
   }
 
   /**
    * @param int $priority
    */
-  function setPriority($priority) {
+  public function setPriority($priority) {
     $this->priority = $priority;
   }
 
   /**
    * @return DateTimeInterface|null
    */
-  function getScheduledAt() {
+  public function getScheduledAt() {
     return $this->scheduled_at;
   }
 
   /**
    * @param DateTimeInterface|null $scheduled_at
    */
-  function setScheduledAt($scheduled_at) {
+  public function setScheduledAt($scheduled_at) {
     $this->scheduled_at = $scheduled_at;
   }
 
   /**
    * @return DateTimeInterface|null
    */
-  function getProcessedAt() {
+  public function getProcessedAt() {
     return $this->processed_at;
   }
 
   /**
    * @param DateTimeInterface|null $processed_at
    */
-  function setProcessedAt($processed_at) {
+  public function setProcessedAt($processed_at) {
     $this->processed_at = $processed_at;
   }
 
   /**
    * @return array|null
    */
-  function getMeta() {
+  public function getMeta() {
     return $this->meta;
   }
 
   /**
    * @param array|null $meta
    */
-  function setMeta($meta) {
+  public function setMeta($meta) {
     $this->meta = $meta;
   }
 }
diff --git a/lib/Entities/SegmentEntity.php b/lib/Entities/SegmentEntity.php
index db16094c20..d9c134f1cf 100644
--- a/lib/Entities/SegmentEntity.php
+++ b/lib/Entities/SegmentEntity.php
@@ -45,42 +45,42 @@ class SegmentEntity {
   /**
    * @return string
    */
-  function getName() {
+  public function getName() {
     return $this->name;
   }
 
   /**
    * @param string $name
    */
-  function setName($name) {
+  public function setName($name) {
     $this->name = $name;
   }
 
   /**
    * @return string
    */
-  function getType() {
+  public function getType() {
     return $this->type;
   }
 
   /**
    * @param string $type
    */
-  function setType($type) {
+  public function setType($type) {
     $this->type = $type;
   }
 
   /**
    * @return string
    */
-  function getDescription() {
+  public function getDescription() {
     return $this->description;
   }
 
   /**
    * @param string $description
    */
-  function setDescription($description) {
+  public function setDescription($description) {
     $this->description = $description;
   }
 }
diff --git a/lib/Entities/SendingQueueEntity.php b/lib/Entities/SendingQueueEntity.php
index 05a65a1cba..7a9dd3ebde 100644
--- a/lib/Entities/SendingQueueEntity.php
+++ b/lib/Entities/SendingQueueEntity.php
@@ -84,120 +84,120 @@ class SendingQueueEntity {
   /**
    * @return array|null
    */
-  function getNewsletterRenderedBody() {
+  public function getNewsletterRenderedBody() {
     return $this->newsletter_rendered_body;
   }
 
   /**
    * @param array|null $newsletter_rendered_body
    */
-  function setNewsletterRenderedBody($newsletter_rendered_body) {
+  public function setNewsletterRenderedBody($newsletter_rendered_body) {
     $this->newsletter_rendered_body = $newsletter_rendered_body;
   }
 
   /**
    * @return string|null
    */
-  function getNewsletterRenderedSubject() {
+  public function getNewsletterRenderedSubject() {
     return $this->newsletter_rendered_subject;
   }
 
   /**
    * @param string|null $newsletter_rendered_subject
    */
-  function setNewsletterRenderedSubject($newsletter_rendered_subject) {
+  public function setNewsletterRenderedSubject($newsletter_rendered_subject) {
     $this->newsletter_rendered_subject = $newsletter_rendered_subject;
   }
 
   /**
    * @return string|null
    */
-  function getSubscribers() {
+  public function getSubscribers() {
     return $this->subscribers;
   }
 
   /**
    * @param string|null $subscribers
    */
-  function setSubscribers($subscribers) {
+  public function setSubscribers($subscribers) {
     $this->subscribers = $subscribers;
   }
 
   /**
    * @return int
    */
-  function getCountTotal() {
+  public function getCountTotal() {
     return $this->count_total;
   }
 
   /**
    * @param int $count_total
    */
-  function setCountTotal($count_total) {
+  public function setCountTotal($count_total) {
     $this->count_total = $count_total;
   }
 
   /**
    * @return int
    */
-  function getCountProcessed() {
+  public function getCountProcessed() {
     return $this->count_processed;
   }
 
   /**
    * @param int $count_processed
    */
-  function setCountProcessed($count_processed) {
+  public function setCountProcessed($count_processed) {
     $this->count_processed = $count_processed;
   }
 
   /**
    * @return int
    */
-  function getCountToProcess() {
+  public function getCountToProcess() {
     return $this->count_to_process;
   }
 
   /**
    * @param int $count_to_process
    */
-  function setCountToProcess($count_to_process) {
+  public function setCountToProcess($count_to_process) {
     $this->count_to_process = $count_to_process;
   }
 
   /**
    * @return array|null
    */
-  function getMeta() {
+  public function getMeta() {
     return $this->meta;
   }
 
   /**
    * @param array|null $meta
    */
-  function setMeta($meta) {
+  public function setMeta($meta) {
     $this->meta = $meta;
   }
 
   /**
    * @return ScheduledTaskEntity
    */
-  function getTask() {
+  public function getTask() {
     return $this->task;
   }
 
-  function setTask(ScheduledTaskEntity $task) {
+  public function setTask(ScheduledTaskEntity $task) {
     $this->task = $task;
   }
 
   /**
    * @return NewsletterEntity
    */
-  function getNewsletter() {
+  public function getNewsletter() {
     return $this->newsletter;
   }
 
-  function setNewsletter(NewsletterEntity $newsletter) {
+  public function setNewsletter(NewsletterEntity $newsletter) {
     $this->newsletter = $newsletter;
   }
 }
diff --git a/lib/Entities/StatsNotificationEntity.php b/lib/Entities/StatsNotificationEntity.php
index c6c7625b2a..6150e1536f 100644
--- a/lib/Entities/StatsNotificationEntity.php
+++ b/lib/Entities/StatsNotificationEntity.php
@@ -28,7 +28,7 @@ class StatsNotificationEntity {
    */
   private $task;
 
-  function __construct(NewsletterEntity $newsletter, ScheduledTaskEntity $task) {
+  public function __construct(NewsletterEntity $newsletter, ScheduledTaskEntity $task) {
     $this->newsletter = $newsletter;
     $this->task = $task;
   }
diff --git a/lib/Features/FeatureFlagsController.php b/lib/Features/FeatureFlagsController.php
index f41f521448..edf27871fe 100644
--- a/lib/Features/FeatureFlagsController.php
+++ b/lib/Features/FeatureFlagsController.php
@@ -12,12 +12,12 @@ class FeatureFlagsController {
   /** @var FeatureFlagsRepository */
   private $feature_flags_repository;
 
-  function __construct(FeaturesController $features_controller, FeatureFlagsRepository $feature_flags_repository) {
+  public function __construct(FeaturesController $features_controller, FeatureFlagsRepository $feature_flags_repository) {
     $this->features_controller = $features_controller;
     $this->feature_flags_repository = $feature_flags_repository;
   }
 
-  function set($name, $value) {
+  public function set($name, $value) {
     if (!$this->features_controller->exists($name)) {
       throw new \RuntimeException("Feature '$name' does not exist'");
     }
@@ -25,7 +25,7 @@ class FeatureFlagsController {
     $this->feature_flags_repository->createOrUpdate(['name' => $name, 'value' => $value]);
   }
 
-  function getAll() {
+  public function getAll() {
     $flags = $this->feature_flags_repository->findAll();
     $flagsMap = array_combine(
       array_map(
diff --git a/lib/Features/FeaturesController.php b/lib/Features/FeaturesController.php
index 18276d8579..0b0942efba 100644
--- a/lib/Features/FeaturesController.php
+++ b/lib/Features/FeaturesController.php
@@ -29,7 +29,7 @@ class FeaturesController {
   }
 
   /** @return bool */
-  function isSupported($feature) {
+  public function isSupported($feature) {
     if (!$this->exists($feature)) {
       throw new \RuntimeException("Unknown feature '$feature'");
     }
@@ -43,17 +43,17 @@ class FeaturesController {
   }
 
   /** @return bool */
-  function exists($feature) {
+  public function exists($feature) {
     return array_key_exists($feature, $this->defaults);
   }
 
   /** @return array */
-  function getDefaults() {
+  public function getDefaults() {
     return $this->defaults;
   }
 
   /** @return array */
-  function getAllFlags() {
+  public function getAllFlags() {
     $this->ensureFlagsLoaded();
     return $this->flags;
   }
diff --git a/lib/Form/AssetsController.php b/lib/Form/AssetsController.php
index 5a9106e6a7..a09db0e9cc 100644
--- a/lib/Form/AssetsController.php
+++ b/lib/Form/AssetsController.php
@@ -20,7 +20,7 @@ class AssetsController {
 
   const RECAPTCHA_API_URL = 'https://www.google.com/recaptcha/api.js?onload=reCaptchaCallback&render=explicit';
 
-  function __construct(WPFunctions $wp, BasicRenderer $renderer, SettingsController $settings) {
+  public function __construct(WPFunctions $wp, BasicRenderer $renderer, SettingsController $settings) {
     $this->wp = $wp;
     $this->renderer = $renderer;
     $this->settings = $settings;
@@ -30,7 +30,7 @@ class AssetsController {
    * Returns assets scripts tags as string
    * @return string
    */
-  function printScripts() {
+  public function printScripts() {
     ob_start();
     $this->wp->wpPrintScripts('jquery');
     $this->wp->wpPrintScripts('mailpoet_vendor');
@@ -41,7 +41,7 @@ class AssetsController {
     return $scripts;
   }
 
-  function setupFrontEndDependencies() {
+  public function setupFrontEndDependencies() {
     $this->wp->wpEnqueueStyle(
       'mailpoet_public',
       Env::$assets_url . '/dist/css/' . $this->renderer->getCssAsset('public.css')
@@ -96,7 +96,7 @@ EOL;
     );
   }
 
-  function setupAdminWidgetPageDependencies() {
+  public function setupAdminWidgetPageDependencies() {
     $this->wp->wpEnqueueScript(
       'mailpoet_vendor',
       Env::$assets_url . '/dist/js/' . $this->renderer->getJsAsset('vendor.js'),
diff --git a/lib/Form/Block/Checkbox.php b/lib/Form/Block/Checkbox.php
index 0d2843a486..8da38b4307 100644
--- a/lib/Form/Block/Checkbox.php
+++ b/lib/Form/Block/Checkbox.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Checkbox extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $field_name = 'data[' . static::getFieldName($block) . ']';
diff --git a/lib/Form/Block/Date.php b/lib/Form/Block/Date.php
index aad1ae882c..efddc0c5c4 100644
--- a/lib/Form/Block/Date.php
+++ b/lib/Form/Block/Date.php
@@ -7,7 +7,7 @@ use MailPoetVendor\Carbon\Carbon;
 
 class Date extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
     $html .= '<p class="mailpoet_paragraph">';
     $html .= static::renderLabel($block);
@@ -103,7 +103,7 @@ class Date extends Base {
     return $html;
   }
 
-  static function getDateTypes() {
+  public static function getDateTypes() {
     return [
       'year_month_day' => WPFunctions::get()->__('Year, month, day', 'mailpoet'),
       'year_month' => WPFunctions::get()->__('Year, month', 'mailpoet'),
@@ -112,7 +112,7 @@ class Date extends Base {
     ];
   }
 
-  static function getDateFormats() {
+  public static function getDateFormats() {
     return [
       'year_month_day' => ['MM/DD/YYYY', 'DD/MM/YYYY', 'YYYY/MM/DD'],
       'year_month' => ['MM/YYYY', 'YYYY/MM'],
@@ -120,14 +120,14 @@ class Date extends Base {
       'month' => ['MM'],
     ];
   }
-  static function getMonthNames() {
+  public static function getMonthNames() {
     return [__('January', 'mailpoet'), WPFunctions::get()->__('February', 'mailpoet'), WPFunctions::get()->__('March', 'mailpoet'), WPFunctions::get()->__('April', 'mailpoet'),
       WPFunctions::get()->__('May', 'mailpoet'), WPFunctions::get()->__('June', 'mailpoet'), WPFunctions::get()->__('July', 'mailpoet'), WPFunctions::get()->__('August', 'mailpoet'), WPFunctions::get()->__('September', 'mailpoet'),
       WPFunctions::get()->__('October', 'mailpoet'), WPFunctions::get()->__('November', 'mailpoet'), WPFunctions::get()->__('December', 'mailpoet'),
     ];
   }
 
-  static function getMonths($block = []) {
+  public static function getMonths($block = []) {
     $defaults = [
       'selected' => null,
     ];
@@ -152,7 +152,7 @@ class Date extends Base {
     return $html;
   }
 
-  static function getYears($block = []) {
+  public static function getYears($block = []) {
     $defaults = [
       'selected' => null,
       'from' => (int)strftime('%Y') - 100,
@@ -181,7 +181,7 @@ class Date extends Base {
     return $html;
   }
 
-  static function getDays($block = []) {
+  public static function getDays($block = []) {
     $defaults = [
       'selected' => null,
     ];
@@ -207,7 +207,7 @@ class Date extends Base {
     return $html;
   }
 
-  static function convertDateToDatetime($date, $date_format) {
+  public static function convertDateToDatetime($date, $date_format) {
     $datetime = false;
     if ($date_format === 'datetime') {
       $datetime = $date;
diff --git a/lib/Form/Block/Divider.php b/lib/Form/Block/Divider.php
index 255ad38a81..f3605ddf1f 100644
--- a/lib/Form/Block/Divider.php
+++ b/lib/Form/Block/Divider.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Divider {
 
-  static function render() {
+  public static function render() {
     return '<hr class="mailpoet_divider" />';
   }
 }
\ No newline at end of file
diff --git a/lib/Form/Block/Html.php b/lib/Form/Block/Html.php
index 39eb1803ef..7710e7926a 100644
--- a/lib/Form/Block/Html.php
+++ b/lib/Form/Block/Html.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Html {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
     $text = '';
 
diff --git a/lib/Form/Block/Radio.php b/lib/Form/Block/Radio.php
index 0d9b594d3d..8d265af054 100644
--- a/lib/Form/Block/Radio.php
+++ b/lib/Form/Block/Radio.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Radio extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $field_name = 'data[' . static::getFieldName($block) . ']';
diff --git a/lib/Form/Block/Segment.php b/lib/Form/Block/Segment.php
index 50008bb816..5d5c507357 100644
--- a/lib/Form/Block/Segment.php
+++ b/lib/Form/Block/Segment.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Segment extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $field_name = 'data[' . static::getFieldName($block) . ']';
diff --git a/lib/Form/Block/Select.php b/lib/Form/Block/Select.php
index b85b39b2a2..6b6f110413 100644
--- a/lib/Form/Block/Select.php
+++ b/lib/Form/Block/Select.php
@@ -6,7 +6,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class Select extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $field_name = 'data[' . static::getFieldName($block) . ']';
diff --git a/lib/Form/Block/Submit.php b/lib/Form/Block/Submit.php
index 2be63d81fb..721af85c72 100644
--- a/lib/Form/Block/Submit.php
+++ b/lib/Form/Block/Submit.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Submit extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $html .= '<p class="mailpoet_paragraph"><input type="submit" class="mailpoet_submit" ';
diff --git a/lib/Form/Block/Text.php b/lib/Form/Block/Text.php
index 76abf103cf..914d1ab237 100644
--- a/lib/Form/Block/Text.php
+++ b/lib/Form/Block/Text.php
@@ -4,7 +4,7 @@ namespace MailPoet\Form\Block;
 
 class Text extends Base {
 
-  static function render($block) {
+  public static function render($block) {
     $type = 'text';
     $automation_id = ' ';
     if ($block['id'] === 'email') {
diff --git a/lib/Form/Block/Textarea.php b/lib/Form/Block/Textarea.php
index 1342b57ee6..d256839369 100644
--- a/lib/Form/Block/Textarea.php
+++ b/lib/Form/Block/Textarea.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Form\Block;
 
 class Textarea extends Base {
-  static function render($block) {
+  public static function render($block) {
     $html = '';
 
     $html .= '<p class="mailpoet_paragraph">';
diff --git a/lib/Form/Renderer.php b/lib/Form/Renderer.php
index 8a78f5321a..e7af4c41ec 100644
--- a/lib/Form/Renderer.php
+++ b/lib/Form/Renderer.php
@@ -8,13 +8,13 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class Renderer {
   // public: rendering method
-  static function render($form = []) {
+  public static function render($form = []) {
     $html = static::renderStyles($form);
     $html .= static::renderHTML($form);
     return $html;
   }
 
-  static function renderStyles($form = [], $prefix = null) {
+  public static function renderStyles($form = [], $prefix = null) {
     $styles = new Util\Styles();
 
     $html = '<style type="text/css">';
@@ -25,14 +25,14 @@ class Renderer {
     return $html;
   }
 
-  static function renderHTML($form = []) {
+  public static function renderHTML($form = []) {
     if (isset($form['body']) && !empty($form['body'])) {
       return static::renderBlocks($form['body']);
     }
     return '';
   }
 
-  static function getStyles($form = []) {
+  public static function getStyles($form = []) {
     if (isset($form['styles'])
     && strlen(trim($form['styles'])) > 0) {
       return strip_tags($form['styles']);
@@ -42,7 +42,7 @@ class Renderer {
     }
   }
 
-  static function renderBlocks($blocks = [], $honeypot_enabled = true) {
+  public static function renderBlocks($blocks = [], $honeypot_enabled = true) {
     $settings = SettingsController::getInstance();
     // add honeypot for spambots
     $html = ($honeypot_enabled) ?
@@ -76,7 +76,7 @@ class Renderer {
     return $html;
   }
 
-  static function renderBlock($block = []) {
+  public static function renderBlock($block = []) {
     $html = '';
     switch ($block['type']) {
       case 'html':
diff --git a/lib/Form/Util/Export.php b/lib/Form/Util/Export.php
index cff6e319bf..70d10e7a68 100644
--- a/lib/Form/Util/Export.php
+++ b/lib/Form/Util/Export.php
@@ -7,7 +7,7 @@ use MailPoet\Form\Widget;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Export {
-  static function getAll($form = null) {
+  public static function getAll($form = null) {
     return [
       'html'      => static::get('html', $form),
       'php'       => static::get('php', $form),
@@ -16,7 +16,7 @@ class Export {
     ];
   }
 
-  static function get($type = 'html', $form = null) {
+  public static function get($type = 'html', $form = null) {
     switch ($type) {
       case 'iframe':
         // generate url to load iframe's content
diff --git a/lib/Form/Util/Styles.php b/lib/Form/Util/Styles.php
index 91ad7b581a..dd14752ca6 100644
--- a/lib/Form/Util/Styles.php
+++ b/lib/Form/Util/Styles.php
@@ -87,7 +87,7 @@ EOL;
   /**
    * @param FeaturesController $features_controller
    */
-  function __construct(
+  public function __construct(
     FeaturesController $features_controller = null
   ) {
     if ($features_controller === null) {
@@ -96,7 +96,7 @@ EOL;
     $this->features_controller = $features_controller;
   }
 
-  function getDefaultStyles() {
+  public function getDefaultStyles() {
     if ($this->features_controller->isSupported(FeaturesController::NEW_FORM_EDITOR)) {
       $text_input_width = 'width: 100%;';
     } else {
@@ -105,7 +105,7 @@ EOL;
     return str_replace('[TEXT_INPUTS_WIDTH_RULE]', $text_input_width, $this->default_styles);
   }
 
-  function render($stylesheet, $prefix = '') {
+  public function render($stylesheet, $prefix = '') {
     if (!$stylesheet) return;
     $styles = new CSSParser($stylesheet);
     $styles = $styles->parse();
diff --git a/lib/Form/Widget.php b/lib/Form/Widget.php
index 3555858e6f..648e8a1614 100644
--- a/lib/Form/Widget.php
+++ b/lib/Form/Widget.php
@@ -17,7 +17,7 @@ class Widget extends \WP_Widget {
   /** @var AssetsController */
   private $assets_controller;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct(
       'mailpoet_form',
       WPFunctions::get()->__('MailPoet 3 Form', 'mailpoet'),
@@ -36,7 +36,7 @@ class Widget extends \WP_Widget {
     }
   }
 
-  function setupIframe() {
+  public function setupIframe() {
     $form_id = (isset($_GET['mailpoet_form_iframe']) ? (int)$_GET['mailpoet_form_iframe'] : 0);
     if (!$form_id || !Form::findOne($form_id)) return;
 
@@ -140,7 +140,7 @@ class Widget extends \WP_Widget {
       <a href="javascript:;" onClick="createSubscriptionForm()" class="mailpoet_form_new"><?php WPFunctions::get()->_e('Create a new form', 'mailpoet'); ?></a>
     </p>
     <script type="text/javascript">
-    function createSubscriptionForm() {
+    public function createSubscriptionForm() {
         MailPoet.Ajax.post({
           endpoint: 'forms',
           action: 'create',
@@ -167,7 +167,7 @@ class Widget extends \WP_Widget {
   /**
    * Output the widget itself.
    */
-  function widget($args, $instance = null) {
+  public function widget($args, $instance = null) {
     $this->assets_controller->setupFrontEndDependencies();
 
     // turn $args into variables
diff --git a/lib/Helpscout/Beacon.php b/lib/Helpscout/Beacon.php
index 57a6da1e75..2a74a12956 100644
--- a/lib/Helpscout/Beacon.php
+++ b/lib/Helpscout/Beacon.php
@@ -17,12 +17,12 @@ class Beacon {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function getData() {
+  public function getData() {
     global $wpdb;
     $db_version = $wpdb->get_var('SELECT @@VERSION');
     $mta = $this->settings->get('mta');
diff --git a/lib/Listing/BulkActionController.php b/lib/Listing/BulkActionController.php
index 4057cd9a2b..bd867aa0c6 100644
--- a/lib/Listing/BulkActionController.php
+++ b/lib/Listing/BulkActionController.php
@@ -9,12 +9,12 @@ class BulkActionController {
   /** @var Handler */
   private $handler;
 
-  function __construct(BulkActionFactory $factory, Handler $handler) {
+  public function __construct(BulkActionFactory $factory, Handler $handler) {
     $this->factory = $factory;
     $this->handler = $handler;
   }
 
-  function apply($model_class, array $data) {
+  public function apply($model_class, array $data) {
     $bulk_action_method = 'bulk' . ucfirst($data['action']);
     unset($data['action']);
 
diff --git a/lib/Listing/BulkActionFactory.php b/lib/Listing/BulkActionFactory.php
index a618dd5f53..2fa272c962 100644
--- a/lib/Listing/BulkActionFactory.php
+++ b/lib/Listing/BulkActionFactory.php
@@ -6,12 +6,12 @@ class BulkActionFactory {
   /** @var array */
   private $actions = [];
 
-  function registerAction($model_class, $bulk_action_method, $action_class) {
+  public function registerAction($model_class, $bulk_action_method, $action_class) {
     $this->ensureMethodExists($action_class, $bulk_action_method);
     $this->actions[$model_class][$bulk_action_method] = $action_class;
   }
 
-  function getActionClass($model_class, $bulk_action_method) {
+  public function getActionClass($model_class, $bulk_action_method) {
     $resulting_class = $model_class;
     if (!empty($this->actions[$model_class][$bulk_action_method])) {
       $resulting_class = $this->actions[$model_class][$bulk_action_method];
diff --git a/lib/Listing/Handler.php b/lib/Listing/Handler.php
index be33d88771..ef1625c0fa 100644
--- a/lib/Listing/Handler.php
+++ b/lib/Listing/Handler.php
@@ -8,7 +8,7 @@ use MailPoetVendor\Paris\ORMWrapper;
 class Handler {
   const DEFAULT_LIMIT_PER_PAGE = 20;
 
-  function getSelection($model_class, array $data) {
+  public function getSelection($model_class, array $data) {
     $data = $this->processData($data);
     $table_name = $model_class::$_table;
     $model = Model::factory($model_class);
@@ -34,7 +34,7 @@ class Handler {
     }
   }
 
-  function get($model_class, array $data) {
+  public function get($model_class, array $data) {
     $data = $this->processData($data);
     $table_name = $model_class::$_table;
     $model = Model::factory($model_class);
diff --git a/lib/Listing/PageLimit.php b/lib/Listing/PageLimit.php
index a673ac6751..294c2e162e 100644
--- a/lib/Listing/PageLimit.php
+++ b/lib/Listing/PageLimit.php
@@ -10,11 +10,11 @@ class PageLimit {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function getLimitPerPage($model = null) {
+  public function getLimitPerPage($model = null) {
     if ($model === null) {
       return self::DEFAULT_LIMIT_PER_PAGE;
     }
diff --git a/lib/Logging/LoggerFactory.php b/lib/Logging/LoggerFactory.php
index 2eb093be3f..e314a8fd65 100644
--- a/lib/Logging/LoggerFactory.php
+++ b/lib/Logging/LoggerFactory.php
@@ -36,7 +36,7 @@ class LoggerFactory {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(SettingsController $settings) {
+  public function __construct(SettingsController $settings) {
     $this->settings = $settings;
   }
 
@@ -46,7 +46,7 @@ class LoggerFactory {
    *
    * @return \MailPoetVendor\Monolog\Logger
    */
-  function getLogger($name = 'MailPoet', $attach_processors = WP_DEBUG) {
+  public function getLogger($name = 'MailPoet', $attach_processors = WP_DEBUG) {
     if (!isset($this->logger_instances[$name])) {
       $this->logger_instances[$name] = new \MailPoetVendor\Monolog\Logger($name);
 
@@ -64,7 +64,7 @@ class LoggerFactory {
     return $this->logger_instances[$name];
   }
 
-  static function getInstance() {
+  public static function getInstance() {
     if (!self::$instance instanceof LoggerFactory) {
       self::$instance = new LoggerFactory(SettingsController::getInstance());
     }
diff --git a/lib/Mailer/Mailer.php b/lib/Mailer/Mailer.php
index f1e2d06b00..ef9ad546fa 100644
--- a/lib/Mailer/Mailer.php
+++ b/lib/Mailer/Mailer.php
@@ -32,14 +32,14 @@ class Mailer {
   const METHOD_PHPMAIL = 'PHPMail';
   const METHOD_SMTP = 'SMTP';
 
-  function __construct(SettingsController $settings = null) {
+  public function __construct(SettingsController $settings = null) {
     if (!$settings) {
       $settings = SettingsController::getInstance();
     }
     $this->settings = $settings;
   }
 
-  function init($mailer = false, $sender = false, $reply_to = false, $return_path = false) {
+  public function init($mailer = false, $sender = false, $reply_to = false, $return_path = false) {
     $this->mailer_config = $this->getMailerConfig($mailer);
     $this->sender = $this->getSenderNameAndAddress($sender);
     $this->reply_to = $this->getReplyToNameAndAddress($reply_to);
@@ -47,7 +47,7 @@ class Mailer {
     $this->mailer_instance = $this->buildMailer();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if (!$this->mailer_instance) {
       $this->init();
     }
@@ -134,7 +134,7 @@ class Mailer {
     ];
   }
 
-  function getReplyToNameAndAddress($reply_to = []) {
+  public function getReplyToNameAndAddress($reply_to = []) {
     if (!$reply_to) {
       $reply_to = $this->settings->get('reply_to');
       $reply_to['name'] = (!empty($reply_to['name'])) ?
@@ -155,7 +155,7 @@ class Mailer {
     ];
   }
 
-  function getReturnPathAddress($return_path) {
+  public function getReturnPathAddress($return_path) {
     return ($return_path) ?
       $return_path :
       $this->settings->get('bounce.address');
@@ -164,7 +164,7 @@ class Mailer {
   /**
    * @param  \MailPoet\Models\Subscriber|array $subscriber
    */
-  function formatSubscriberNameAndEmailAddress($subscriber) {
+  public function formatSubscriberNameAndEmailAddress($subscriber) {
     $subscriber = (is_object($subscriber)) ? $subscriber->asArray() : $subscriber;
     if (!is_array($subscriber)) return $subscriber;
     if (isset($subscriber['address'])) $subscriber['email'] = $subscriber['address'];
@@ -183,20 +183,20 @@ class Mailer {
     return $subscriber;
   }
 
-  function encodeAddressNamePart($name) {
+  public function encodeAddressNamePart($name) {
     if (mb_detect_encoding($name) === 'ASCII') return $name;
     // encode non-ASCII string as per RFC 2047 (https://www.ietf.org/rfc/rfc2047.txt)
     return sprintf('=?utf-8?B?%s?=', base64_encode($name));
   }
 
-  static function formatMailerErrorResult(MailerError $error) {
+  public static function formatMailerErrorResult(MailerError $error) {
     return [
       'response' => false,
       'error' => $error,
     ];
   }
 
-  static function formatMailerSendSuccessResult() {
+  public static function formatMailerSendSuccessResult() {
     return [
       'response' => true,
     ];
diff --git a/lib/Mailer/MailerError.php b/lib/Mailer/MailerError.php
index 088b4bd2f8..8e7d38fc04 100644
--- a/lib/Mailer/MailerError.php
+++ b/lib/Mailer/MailerError.php
@@ -36,7 +36,7 @@ class MailerError {
    * @param int|null $retry_interval
    * @param array $subscribers_errors
    */
-  function __construct($operation, $level, $message = null, $retry_interval = null, array $subscribers_errors = []) {
+  public function __construct($operation, $level, $message = null, $retry_interval = null, array $subscribers_errors = []) {
     $this->operation = $operation;
     $this->level = $level;
     $this->message = $message;
@@ -47,39 +47,39 @@ class MailerError {
   /**
    * @return string
    */
-  function getOperation() {
+  public function getOperation() {
     return $this->operation;
   }
 
   /**
    * @return string
    */
-  function getLevel() {
+  public function getLevel() {
     return $this->level;
   }
 
   /**
    * @return null|string
    */
-  function getMessage() {
+  public function getMessage() {
     return $this->message;
   }
 
   /**
    * @return int|null
    */
-  function getRetryInterval() {
+  public function getRetryInterval() {
     return $this->retry_interval;
   }
 
   /**
    * @return SubscriberError[]
    */
-  function getSubscriberErrors() {
+  public function getSubscriberErrors() {
     return $this->subscribers_errors;
   }
 
-  function getMessageWithFailedSubscribers() {
+  public function getMessageWithFailedSubscribers() {
     $message = $this->message ?: '';
     if (!$this->subscribers_errors) {
       return $message;
diff --git a/lib/Mailer/MailerLog.php b/lib/Mailer/MailerLog.php
index e148313f21..cd81da2dfb 100644
--- a/lib/Mailer/MailerLog.php
+++ b/lib/Mailer/MailerLog.php
@@ -10,7 +10,7 @@ class MailerLog {
   const RETRY_ATTEMPTS_LIMIT = 3;
   const RETRY_INTERVAL = 120; // seconds
 
-  static function getMailerLog($mailer_log = false) {
+  public static function getMailerLog($mailer_log = false) {
     if ($mailer_log) return $mailer_log;
     $settings = SettingsController::getInstance();
     $mailer_log = $settings->get(self::SETTING_NAME);
@@ -20,7 +20,7 @@ class MailerLog {
     return $mailer_log;
   }
 
-  static function createMailerLog() {
+  public static function createMailerLog() {
     $mailer_log = [
       'sent' => null,
       'started' => time(),
@@ -34,17 +34,17 @@ class MailerLog {
     return $mailer_log;
   }
 
-  static function resetMailerLog() {
+  public static function resetMailerLog() {
     return self::createMailerLog();
   }
 
-  static function updateMailerLog($mailer_log) {
+  public static function updateMailerLog($mailer_log) {
     $settings = SettingsController::getInstance();
     $settings->set(self::SETTING_NAME, $mailer_log);
     return $mailer_log;
   }
 
-  static function enforceExecutionRequirements($mailer_log = false) {
+  public static function enforceExecutionRequirements($mailer_log = false) {
     $mailer_log = self::getMailerLog($mailer_log);
     if ($mailer_log['retry_attempt'] === self::RETRY_ATTEMPTS_LIMIT) {
       $mailer_log = self::pauseSending($mailer_log);
@@ -66,14 +66,14 @@ class MailerLog {
     }
   }
 
-  static function pauseSending($mailer_log) {
+  public static function pauseSending($mailer_log) {
     $mailer_log['status'] = self::STATUS_PAUSED;
     $mailer_log['retry_attempt'] = null;
     $mailer_log['retry_at'] = null;
     return self::updateMailerLog($mailer_log);
   }
 
-  static function resumeSending() {
+  public static function resumeSending() {
     return self::resetMailerLog();
   }
 
@@ -86,7 +86,7 @@ class MailerLog {
    *
    * @throws \Exception
    */
-  static function processNonBlockingError($operation, $error_message, $retry_interval = self::RETRY_INTERVAL) {
+  public static function processNonBlockingError($operation, $error_message, $retry_interval = self::RETRY_INTERVAL) {
     $mailer_log = self::getMailerLog();
     $mailer_log['retry_at'] = time() + $retry_interval;
     $mailer_log = self::setError($mailer_log, $operation, $error_message);
@@ -104,7 +104,7 @@ class MailerLog {
    *
    * @throws \Exception
    */
-  static function processError($operation, $error_message, $error_code = null, $pause_sending = false) {
+  public static function processError($operation, $error_message, $error_code = null, $pause_sending = false) {
     $mailer_log = self::getMailerLog();
     $mailer_log['retry_attempt']++;
     $mailer_log['retry_at'] = time() + self::RETRY_INTERVAL;
@@ -116,7 +116,7 @@ class MailerLog {
     self::enforceExecutionRequirements();
   }
 
-  static function setError($mailer_log, $operation, $error_message, $error_code = null) {
+  public static function setError($mailer_log, $operation, $error_message, $error_code = null) {
     $mailer_log['error'] = [
       'operation' => $operation,
       'error_message' => $error_message,
@@ -127,12 +127,12 @@ class MailerLog {
     return $mailer_log;
   }
 
-  static function getError($mailer_log = false) {
+  public static function getError($mailer_log = false) {
     $mailer_log = self::getMailerLog($mailer_log);
     return isset($mailer_log['error']) ? $mailer_log['error'] : null;
   }
 
-  static function incrementSentCount() {
+  public static function incrementSentCount() {
     $mailer_log = self::getMailerLog();
     // do not increment count if sending limit is reached
     if (self::isSendingLimitReached($mailer_log)) return;
@@ -144,14 +144,14 @@ class MailerLog {
     return self::updateMailerLog($mailer_log);
   }
 
-  static function clearSendingErrorLog($mailer_log) {
+  public static function clearSendingErrorLog($mailer_log) {
     $mailer_log['retry_attempt'] = null;
     $mailer_log['retry_at'] = null;
     $mailer_log['error'] = null;
     return self::updateMailerLog($mailer_log);
   }
 
-  static function isSendingLimitReached($mailer_log = false) {
+  public static function isSendingLimitReached($mailer_log = false) {
     $settings = SettingsController::getInstance();
     $mailer_config = $settings->get(Mailer::MAILER_CONFIG_SETTING_NAME);
     // do not enforce sending limit for MailPoet's sending method
@@ -174,7 +174,7 @@ class MailerLog {
     return false;
   }
 
-  static function isSendingPaused($mailer_log = false) {
+  public static function isSendingPaused($mailer_log = false) {
     $mailer_log = self::getMailerLog($mailer_log);
     return $mailer_log['status'] === self::STATUS_PAUSED;
   }
diff --git a/lib/Mailer/MetaInfo.php b/lib/Mailer/MetaInfo.php
index 1474c5c424..0ceaad996a 100644
--- a/lib/Mailer/MetaInfo.php
+++ b/lib/Mailer/MetaInfo.php
@@ -7,19 +7,19 @@ use MailPoet\Models\Newsletter;
 use MailPoet\Models\Subscriber;
 
 class MetaInfo {
-  function getSendingTestMetaInfo() {
+  public function getSendingTestMetaInfo() {
     return $this->makeMetaInfo('sending_test', 'unknown', 'administrator');
   }
 
-  function getPreviewMetaInfo() {
+  public function getPreviewMetaInfo() {
     return $this->makeMetaInfo('preview', 'unknown', 'administrator');
   }
 
-  function getStatsNotificationMetaInfo() {
+  public function getStatsNotificationMetaInfo() {
     return $this->makeMetaInfo('email_stats_notification', 'unknown', 'administrator');
   }
 
-  function getWordPressTransactionalMetaInfo(SubscriberEntity $subscriber = null) {
+  public function getWordPressTransactionalMetaInfo(SubscriberEntity $subscriber = null) {
     return $this->makeMetaInfo(
       'transactional',
       $subscriber ? $subscriber->getStatus() : 'unknown',
@@ -27,15 +27,15 @@ class MetaInfo {
     );
   }
 
-  function getConfirmationMetaInfo(Subscriber $subscriber) {
+  public function getConfirmationMetaInfo(Subscriber $subscriber) {
     return $this->makeMetaInfo('confirmation', $subscriber->status, $subscriber->source);
   }
 
-  function getNewSubscriberNotificationMetaInfo() {
+  public function getNewSubscriberNotificationMetaInfo() {
     return $this->makeMetaInfo('new_subscriber_notification', 'unknown', 'administrator');
   }
 
-  function getNewsletterMetaInfo($newsletter, Subscriber $subscriber) {
+  public function getNewsletterMetaInfo($newsletter, Subscriber $subscriber) {
     $type = 'unknown';
     switch ($newsletter->type) {
       case Newsletter::TYPE_AUTOMATIC:
diff --git a/lib/Mailer/Methods/AmazonSES.php b/lib/Mailer/Methods/AmazonSES.php
index 4ffb31019e..702f317788 100644
--- a/lib/Mailer/Methods/AmazonSES.php
+++ b/lib/Mailer/Methods/AmazonSES.php
@@ -38,7 +38,7 @@ class AmazonSES {
 
   private $wp;
 
-  function __construct(
+  public function __construct(
     $region,
     $access_key,
     $secret_key,
@@ -71,7 +71,7 @@ class AmazonSES {
     $this->blacklist = new BlacklistCheck();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if ($this->blacklist->isBlacklisted($subscriber)) {
       $error = $this->error_mapper->getBlacklistError($subscriber);
       return Mailer::formatMailerErrorResult($error);
@@ -97,7 +97,7 @@ class AmazonSES {
     return Mailer::formatMailerSendSuccessResult();
   }
 
-  function getBody($newsletter, $subscriber, $extra_params = []) {
+  public function getBody($newsletter, $subscriber, $extra_params = []) {
     $this->message = $this->createMessage($newsletter, $subscriber, $extra_params);
     $body = [
       'Action' => 'SendRawEmail',
@@ -108,7 +108,7 @@ class AmazonSES {
     return $body;
   }
 
-  function createMessage($newsletter, $subscriber, $extra_params = []) {
+  public function createMessage($newsletter, $subscriber, $extra_params = []) {
     $message = Swift_Message::newInstance()
       ->setTo($this->processSubscriber($subscriber))
       ->setFrom([
@@ -133,11 +133,11 @@ class AmazonSES {
     return $message;
   }
 
-  function encodeMessage(Swift_Message $message) {
+  public function encodeMessage(Swift_Message $message) {
     return base64_encode($message->toString());
   }
 
-  function processSubscriber($subscriber) {
+  public function processSubscriber($subscriber) {
     preg_match('!(?P<name>.*?)\s<(?P<email>.*?)>!', $subscriber, $subscriber_data);
     if (!isset($subscriber_data['email'])) {
       $subscriber_data = [
@@ -150,7 +150,7 @@ class AmazonSES {
     ];
   }
 
-  function request($newsletter, $subscriber, $extra_params = []) {
+  public function request($newsletter, $subscriber, $extra_params = []) {
     $body = array_map('urlencode', $this->getBody($newsletter, $subscriber, $extra_params));
     return [
       'timeout' => 10,
@@ -165,7 +165,7 @@ class AmazonSES {
     ];
   }
 
-  function signRequest($body) {
+  public function signRequest($body) {
     $string_to_sign = $this->createStringToSign(
       $this->getCredentialScope(),
       $this->getCanonicalRequest($body)
@@ -184,7 +184,7 @@ class AmazonSES {
       $signature);
   }
 
-  function getCredentialScope() {
+  public function getCredentialScope() {
     return sprintf(
       '%s/%s/%s/%s',
       $this->date_without_time,
@@ -193,7 +193,7 @@ class AmazonSES {
       $this->aws_termination_string);
   }
 
-  function getCanonicalRequest($body) {
+  public function getCanonicalRequest($body) {
     return implode("\n", [
       'POST',
       '/',
@@ -206,7 +206,7 @@ class AmazonSES {
     ]);
   }
 
-  function createStringToSign($credential_scope, $canonical_request) {
+  public function createStringToSign($credential_scope, $canonical_request) {
     return implode("\n", [
       $this->aws_signing_algorithm,
       $this->date,
@@ -215,7 +215,7 @@ class AmazonSES {
     ]);
   }
 
-  function getSigningKey() {
+  public function getSigningKey() {
     $date_key = hash_hmac(
       $this->hash_algorithm,
       $this->date_without_time,
diff --git a/lib/Mailer/Methods/Common/BlacklistCheck.php b/lib/Mailer/Methods/Common/BlacklistCheck.php
index 6bb22aa5b0..003c44e9cf 100644
--- a/lib/Mailer/Methods/Common/BlacklistCheck.php
+++ b/lib/Mailer/Methods/Common/BlacklistCheck.php
@@ -15,7 +15,7 @@ class BlacklistCheck {
     $this->blacklist = $blacklist;
   }
 
-  function isBlacklisted($subscriber) {
+  public function isBlacklisted($subscriber) {
     $email = $this->getSubscriberEmailForBlacklistCheck($subscriber);
     return $this->blacklist->isBlacklisted($email);
   }
diff --git a/lib/Mailer/Methods/ErrorMappers/AmazonSESMapper.php b/lib/Mailer/Methods/ErrorMappers/AmazonSESMapper.php
index 14b2aaeec6..7364c9ec37 100644
--- a/lib/Mailer/Methods/ErrorMappers/AmazonSESMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/AmazonSESMapper.php
@@ -14,7 +14,7 @@ class AmazonSESMapper {
 
   const METHOD = Mailer::METHOD_AMAZONSES;
 
-  function getErrorFromException(\Exception $e, $subscriber) {
+  public function getErrorFromException(\Exception $e, $subscriber) {
     $level = MailerError::LEVEL_HARD;
     if ($e instanceof Swift_RfcComplianceException) {
       $level = MailerError::LEVEL_SOFT;
@@ -27,7 +27,7 @@ class AmazonSESMapper {
    * @see https://docs.aws.amazon.com/ses/latest/DeveloperGuide/api-error-codes.html
    * @return MailerError
    */
-  function getErrorFromResponse($response, $subscriber) {
+  public function getErrorFromResponse($response, $subscriber) {
     $message = ($response) ?
       $response->Error->Message->__toString() :
       sprintf(WPFunctions::get()->__('%s has returned an unknown error.', 'mailpoet'), Mailer::METHOD_AMAZONSES);
diff --git a/lib/Mailer/Methods/ErrorMappers/BlacklistErrorMapperTrait.php b/lib/Mailer/Methods/ErrorMappers/BlacklistErrorMapperTrait.php
index af823c1625..768fd9383a 100644
--- a/lib/Mailer/Methods/ErrorMappers/BlacklistErrorMapperTrait.php
+++ b/lib/Mailer/Methods/ErrorMappers/BlacklistErrorMapperTrait.php
@@ -7,7 +7,7 @@ use MailPoet\Mailer\SubscriberError;
 use MailPoet\WP\Functions as WPFunctions;
 
 trait BlacklistErrorMapperTrait {
-  function getBlacklistError($subscriber) {
+  public function getBlacklistError($subscriber) {
     $message = sprintf(WPFunctions::get()->__('%s has returned an unknown error.', 'mailpoet'), self::METHOD);
     $subscriber_errors = [new SubscriberError($subscriber, null)];
     return new MailerError(MailerError::OPERATION_SEND, MailerError::LEVEL_SOFT, $message, null, $subscriber_errors);
diff --git a/lib/Mailer/Methods/ErrorMappers/ConnectionErrorMapperTrait.php b/lib/Mailer/Methods/ErrorMappers/ConnectionErrorMapperTrait.php
index 649b9e8a7c..aa85081be4 100644
--- a/lib/Mailer/Methods/ErrorMappers/ConnectionErrorMapperTrait.php
+++ b/lib/Mailer/Methods/ErrorMappers/ConnectionErrorMapperTrait.php
@@ -5,7 +5,7 @@ namespace MailPoet\Mailer\Methods\ErrorMappers;
 use MailPoet\Mailer\MailerError;
 
 trait ConnectionErrorMapperTrait {
-  function getConnectionError($message) {
+  public function getConnectionError($message) {
     return new MailerError(
       MailerError::OPERATION_CONNECT,
       MailerError::LEVEL_HARD,
diff --git a/lib/Mailer/Methods/ErrorMappers/MailPoetMapper.php b/lib/Mailer/Methods/ErrorMappers/MailPoetMapper.php
index 37f984bdf2..c9a18d3a29 100644
--- a/lib/Mailer/Methods/ErrorMappers/MailPoetMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/MailPoetMapper.php
@@ -18,7 +18,7 @@ class MailPoetMapper {
 
   const TEMPORARY_UNAVAILABLE_RETRY_INTERVAL = 300; // seconds
 
-  function getInvalidApiKeyError() {
+  public function getInvalidApiKeyError() {
     return new MailerError(
       MailerError::OPERATION_SEND,
       MailerError::LEVEL_HARD,
@@ -26,7 +26,7 @@ class MailPoetMapper {
     );
   }
 
-  function getErrorForResult(array $result, $subscribers, $sender = null, $newsletter = null) {
+  public function getErrorForResult(array $result, $subscribers, $sender = null, $newsletter = null) {
     $level = MailerError::LEVEL_HARD;
     $operation = MailerError::OPERATION_SEND;
     $retry_interval = null;
diff --git a/lib/Mailer/Methods/ErrorMappers/PHPMailMapper.php b/lib/Mailer/Methods/ErrorMappers/PHPMailMapper.php
index f75667cc99..789ebd90b8 100644
--- a/lib/Mailer/Methods/ErrorMappers/PHPMailMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/PHPMailMapper.php
@@ -13,7 +13,7 @@ class PHPMailMapper {
 
   const METHOD = Mailer::METHOD_PHPMAIL;
 
-  function getErrorFromException(\Exception $e, $subscriber) {
+  public function getErrorFromException(\Exception $e, $subscriber) {
     $level = MailerError::LEVEL_HARD;
     if (strpos($e->getMessage(), 'Invalid address') === 0) {
       $level = MailerError::LEVEL_SOFT;
@@ -23,7 +23,7 @@ class PHPMailMapper {
     return new MailerError(MailerError::OPERATION_SEND, $level, $e->getMessage(), null, $subscriber_errors);
   }
 
-  function getErrorForSubscriber($subscriber) {
+  public function getErrorForSubscriber($subscriber) {
     $message = sprintf(WPFunctions::get()->__('%s has returned an unknown error.', 'mailpoet'), Mailer::METHOD_PHPMAIL);
     $subscriber_errors = [new SubscriberError($subscriber, null)];
     return new MailerError(MailerError::OPERATION_SEND, MailerError::LEVEL_HARD, $message, null, $subscriber_errors);
diff --git a/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php b/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
index 26e536e639..f0b94fecaa 100644
--- a/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/SMTPMapper.php
@@ -18,7 +18,7 @@ class SMTPMapper {
    * @see https://swiftmailer.symfony.com/docs/sending.html
    * @return MailerError
    */
-  function getErrorFromException(\Exception $e, $subscriber) {
+  public function getErrorFromException(\Exception $e, $subscriber) {
     // remove redundant information appended by Swift logger to exception messages
     $message = explode(PHP_EOL, $e->getMessage());
 
@@ -30,7 +30,7 @@ class SMTPMapper {
     return new MailerError(MailerError::OPERATION_SEND, $level, $message[0], null, $subscriber_errors);
   }
 
-  function getErrorFromLog($log, $subscriber) {
+  public function getErrorFromLog($log, $subscriber) {
     // extract error message from log
     preg_match('/!! (.*?)>>/ism', $log, $message);
     if (!empty($message[1])) {
diff --git a/lib/Mailer/Methods/ErrorMappers/SendGridMapper.php b/lib/Mailer/Methods/ErrorMappers/SendGridMapper.php
index 527d99aadc..683b6dfed6 100644
--- a/lib/Mailer/Methods/ErrorMappers/SendGridMapper.php
+++ b/lib/Mailer/Methods/ErrorMappers/SendGridMapper.php
@@ -13,7 +13,7 @@ class SendGridMapper {
 
   const METHOD = Mailer::METHOD_SENDGRID;
 
-  function getErrorFromResponse($response, $subscriber) {
+  public function getErrorFromResponse($response, $subscriber) {
     $response = (!empty($response['errors'][0])) ?
       $response['errors'][0] :
       sprintf(WPFunctions::get()->__('%s has returned an unknown error.', 'mailpoet'), Mailer::METHOD_SENDGRID);
diff --git a/lib/Mailer/Methods/MailPoet.php b/lib/Mailer/Methods/MailPoet.php
index 45bd8968df..84d75e7549 100644
--- a/lib/Mailer/Methods/MailPoet.php
+++ b/lib/Mailer/Methods/MailPoet.php
@@ -26,7 +26,7 @@ class MailPoet {
   /** @var BlacklistCheck */
   private $blacklist;
 
-  function __construct($api_key, $sender, $reply_to, MailPoetMapper $error_mapper, AuthorizedEmailsController $authorized_emails_controller) {
+  public function __construct($api_key, $sender, $reply_to, MailPoetMapper $error_mapper, AuthorizedEmailsController $authorized_emails_controller) {
     $this->api = new API($api_key);
     $this->sender = $sender;
     $this->reply_to = $reply_to;
@@ -36,7 +36,7 @@ class MailPoet {
     $this->blacklist = new BlacklistCheck();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if ($this->services_checker->isMailPoetAPIKeyValid() === false) {
       return Mailer::formatMailerErrorResult($this->error_mapper->getInvalidApiKeyError());
     }
@@ -65,7 +65,7 @@ class MailPoet {
     }
   }
 
-  function processSendError($result, $subscriber, $newsletter) {
+  public function processSendError($result, $subscriber, $newsletter) {
     if (!empty($result['code']) && $result['code'] === API::RESPONSE_CODE_KEY_INVALID) {
       Bridge::invalidateKey();
     } elseif (!empty($result['code'])
@@ -77,7 +77,7 @@ class MailPoet {
     return $this->error_mapper->getErrorForResult($result, $subscriber, $this->sender, $newsletter);
   }
 
-  function processSubscriber($subscriber) {
+  public function processSubscriber($subscriber) {
     preg_match('!(?P<name>.*?)\s<(?P<email>.*?)>!', $subscriber, $subscriber_data);
     if (!isset($subscriber_data['email'])) {
       $subscriber_data = [
@@ -90,7 +90,7 @@ class MailPoet {
     ];
   }
 
-  function getBody($newsletter, $subscriber, $extra_params = []) {
+  public function getBody($newsletter, $subscriber, $extra_params = []) {
     if (is_array($newsletter) && is_array($subscriber)) {
       $body = [];
       for ($record = 0; $record < count($newsletter); $record++) {
diff --git a/lib/Mailer/Methods/PHPMail.php b/lib/Mailer/Methods/PHPMail.php
index fe50e168ae..3c323d9be4 100644
--- a/lib/Mailer/Methods/PHPMail.php
+++ b/lib/Mailer/Methods/PHPMail.php
@@ -20,7 +20,7 @@ class PHPMail {
   /** @var BlacklistCheck */
   private $blacklist;
 
-  function __construct($sender, $reply_to, $return_path, PHPMailMapper $error_mapper) {
+  public function __construct($sender, $reply_to, $return_path, PHPMailMapper $error_mapper) {
     $this->sender = $sender;
     $this->reply_to = $reply_to;
     $this->return_path = ($return_path) ?
@@ -31,7 +31,7 @@ class PHPMail {
     $this->blacklist = new BlacklistCheck();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if ($this->blacklist->isBlacklisted($subscriber)) {
       $error = $this->error_mapper->getBlacklistError($subscriber);
       return Mailer::formatMailerErrorResult($error);
@@ -50,14 +50,14 @@ class PHPMail {
     }
   }
 
-  function buildMailer() {
+  public function buildMailer() {
     $mailer = new \PHPMailer(true);
     // send using PHP's mail() function
     $mailer->isMail();
     return $mailer;
   }
 
-  function configureMailerWithMessage($newsletter, $subscriber, $extra_params = []) {
+  public function configureMailerWithMessage($newsletter, $subscriber, $extra_params = []) {
     $mailer = $this->mailer;
     $mailer->clearAddresses();
     $mailer->clearCustomHeaders();
@@ -91,7 +91,7 @@ class PHPMail {
     return $mailer;
   }
 
-  function processSubscriber($subscriber) {
+  public function processSubscriber($subscriber) {
     preg_match('!(?P<name>.*?)\s<(?P<email>.*?)>!', $subscriber, $subscriber_data);
     if (!isset($subscriber_data['email'])) {
       $subscriber_data = [
diff --git a/lib/Mailer/Methods/SMTP.php b/lib/Mailer/Methods/SMTP.php
index f4677c5628..2598826003 100644
--- a/lib/Mailer/Methods/SMTP.php
+++ b/lib/Mailer/Methods/SMTP.php
@@ -34,7 +34,7 @@ class SMTP {
 
   private $wp;
 
-  function __construct(
+  public function __construct(
     $host, $port, $authentication, $login = null, $password = null, $encryption,
     $sender, $reply_to, $return_path, SMTPMapper $error_mapper) {
     $this->wp = new WPFunctions;
@@ -56,7 +56,7 @@ class SMTP {
     $this->blacklist = new BlacklistCheck();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if ($this->blacklist->isBlacklisted($subscriber)) {
       $error = $this->error_mapper->getBlacklistError($subscriber);
       return Mailer::formatMailerErrorResult($error);
@@ -77,7 +77,7 @@ class SMTP {
     }
   }
 
-  function buildMailer() {
+  public function buildMailer() {
     $transport = Swift_SmtpTransport::newInstance(
       $this->host, $this->port, $this->encryption);
     $connection_timeout = $this->wp->applyFilters('mailpoet_mailer_smtp_connection_timeout', self::SMTP_CONNECTION_TIMEOUT);
@@ -91,7 +91,7 @@ class SMTP {
     return Swift_Mailer::newInstance($transport);
   }
 
-  function createMessage($newsletter, $subscriber, $extra_params = []) {
+  public function createMessage($newsletter, $subscriber, $extra_params = []) {
     $message = Swift_Message::newInstance()
       ->setTo($this->processSubscriber($subscriber))
       ->setFrom(
@@ -120,7 +120,7 @@ class SMTP {
     return $message;
   }
 
-  function processSubscriber($subscriber) {
+  public function processSubscriber($subscriber) {
     preg_match('!(?P<name>.*?)\s<(?P<email>.*?)>!', $subscriber, $subscriber_data);
     if (!isset($subscriber_data['email'])) {
       $subscriber_data = [
diff --git a/lib/Mailer/Methods/SendGrid.php b/lib/Mailer/Methods/SendGrid.php
index 642825f362..5545fea89d 100644
--- a/lib/Mailer/Methods/SendGrid.php
+++ b/lib/Mailer/Methods/SendGrid.php
@@ -21,7 +21,7 @@ class SendGrid {
 
   private $wp;
 
-  function __construct($api_key, $sender, $reply_to, SendGridMapper $error_mapper) {
+  public function __construct($api_key, $sender, $reply_to, SendGridMapper $error_mapper) {
     $this->api_key = $api_key;
     $this->sender = $sender;
     $this->reply_to = $reply_to;
@@ -30,7 +30,7 @@ class SendGrid {
     $this->blacklist = new BlacklistCheck();
   }
 
-  function send($newsletter, $subscriber, $extra_params = []) {
+  public function send($newsletter, $subscriber, $extra_params = []) {
     if ($this->blacklist->isBlacklisted($subscriber)) {
       $error = $this->error_mapper->getBlacklistError($subscriber);
       return Mailer::formatMailerErrorResult($error);
@@ -51,7 +51,7 @@ class SendGrid {
     return Mailer::formatMailerSendSuccessResult();
   }
 
-  function getBody($newsletter, $subscriber, $extra_params = []) {
+  public function getBody($newsletter, $subscriber, $extra_params = []) {
     $body = [
       'to' => $subscriber,
       'from' => $this->sender['from_email'],
@@ -75,11 +75,11 @@ class SendGrid {
     return $body;
   }
 
-  function auth() {
+  public function auth() {
     return 'Bearer ' . $this->api_key;
   }
 
-  function request($newsletter, $subscriber, $extra_params = []) {
+  public function request($newsletter, $subscriber, $extra_params = []) {
     $body = $this->getBody($newsletter, $subscriber, $extra_params);
     return [
       'timeout' => 10,
diff --git a/lib/Mailer/SubscriberError.php b/lib/Mailer/SubscriberError.php
index 02c112e78b..47f95e94f5 100644
--- a/lib/Mailer/SubscriberError.php
+++ b/lib/Mailer/SubscriberError.php
@@ -14,7 +14,7 @@ class SubscriberError {
    * @param string $email
    * @param string $message|null
    */
-  function __construct($email, $message = null) {
+  public function __construct($email, $message = null) {
     $this->email = $email;
     $this->message = $message;
   }
@@ -22,18 +22,18 @@ class SubscriberError {
   /**
    * @return string
    */
-  function getEmail() {
+  public function getEmail() {
     return $this->email;
   }
 
   /**
    * @return null|string
    */
-  function getMessage() {
+  public function getMessage() {
     return $this->message;
   }
 
-  function __toString() {
+  public function __toString() {
     return $this->message ? $this->email . ': ' . $this->message : $this->email;
   }
 }
diff --git a/lib/Mailer/WordPress/FallbackMailer.php b/lib/Mailer/WordPress/FallbackMailer.php
index 3c3042d086..07d02fe075 100644
--- a/lib/Mailer/WordPress/FallbackMailer.php
+++ b/lib/Mailer/WordPress/FallbackMailer.php
@@ -7,7 +7,7 @@ use MailPoet\Mailer\Mailer;
 class FallbackMailer extends Mailer {
   const FALLBACK_METHOD = self::METHOD_PHPMAIL;
 
-  function init($mailer = false, $sender = false, $reply_to = false, $return_path = false) {
+  public function init($mailer = false, $sender = false, $reply_to = false, $return_path = false) {
     // init is called lazily from when sending, we need to set correct sending method
     parent::init(['method' => self::FALLBACK_METHOD], $sender, $reply_to, $return_path);
   }
diff --git a/lib/Mailer/WordPress/WordPressMailer.php b/lib/Mailer/WordPress/WordPressMailer.php
index f1a9856401..23f5c795a1 100644
--- a/lib/Mailer/WordPress/WordPressMailer.php
+++ b/lib/Mailer/WordPress/WordPressMailer.php
@@ -25,7 +25,7 @@ class WordPressMailer extends \PHPMailer {
   /** @var SubscribersRepository */
   private $subscribers_repository;
 
-  function __construct(
+  public function __construct(
     Mailer $mailer,
     Mailer $fallback_mailer,
     MetaInfo $mailerMetaInfo,
@@ -38,7 +38,7 @@ class WordPressMailer extends \PHPMailer {
     $this->subscribers_repository = $subscribers_repository;
   }
 
-  function send() {
+  public function send() {
     // We need this so that the \PHPMailer class will correctly prepare all the headers.
     $this->Mailer = 'mail';
 
diff --git a/lib/Mailer/WordPress/WordpressMailerReplacer.php b/lib/Mailer/WordPress/WordpressMailerReplacer.php
index 25d5ed0866..710e926235 100644
--- a/lib/Mailer/WordPress/WordpressMailerReplacer.php
+++ b/lib/Mailer/WordPress/WordpressMailerReplacer.php
@@ -21,7 +21,7 @@ class WordpressMailerReplacer {
   /** @var SubscribersRepository */
   private $subscribers_repository;
 
-  function __construct(
+  public function __construct(
     Mailer $mailer,
     MetaInfo $mailerMetaInfo,
     SettingsController $settings,
diff --git a/lib/Models/CustomField.php b/lib/Models/CustomField.php
index e2504c0275..d5d1b42f4d 100644
--- a/lib/Models/CustomField.php
+++ b/lib/Models/CustomField.php
@@ -19,7 +19,7 @@ class CustomField extends Model {
   const TYPE_CHECKBOX = 'checkbox';
   const TYPE_SELECT = 'select';
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->addValidations('name', [
       'required' => WPFunctions::get()->__('Please specify a name.', 'mailpoet'),
@@ -29,7 +29,7 @@ class CustomField extends Model {
     ]);
   }
 
-  function asArray() {
+  public function asArray() {
     $model = parent::asArray();
 
     if (isset($model['params'])) {
@@ -40,7 +40,7 @@ class CustomField extends Model {
     return $model;
   }
 
-  function save() {
+  public function save() {
     if (is_null($this->params)) {
       $this->params = [];
     }
@@ -52,7 +52,7 @@ class CustomField extends Model {
     return parent::save();
   }
 
-  function formatValue($value = null) {
+  public function formatValue($value = null) {
     // format custom field data depending on type
     if (is_array($value) && $this->type === self::TYPE_DATE) {
       $custom_field_data = $this->asArray();
@@ -122,7 +122,7 @@ class CustomField extends Model {
     return $value;
   }
 
-  function subscribers() {
+  public function subscribers() {
     return $this->hasManyThrough(
       __NAMESPACE__ . '\Subscriber',
       __NAMESPACE__ . '\SubscriberCustomField',
@@ -131,7 +131,7 @@ class CustomField extends Model {
     )->selectExpr(MP_SUBSCRIBER_CUSTOM_FIELD_TABLE . '.value');
   }
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     // set name as label by default
     if (empty($data['params']['label']) && isset($data['name'])) {
       $data['params']['label'] = $data['name'];
diff --git a/lib/Models/DynamicSegment.php b/lib/Models/DynamicSegment.php
index e269e94289..dc73eca931 100644
--- a/lib/Models/DynamicSegment.php
+++ b/lib/Models/DynamicSegment.php
@@ -34,23 +34,23 @@ class DynamicSegment extends MailPoetSegment {
     $this->filters = $filters;
   }
 
-  function save() {
+  public function save() {
     $this->set('type', DynamicSegment::TYPE_DYNAMIC);
     return parent::save();
   }
 
-  function dynamicSegmentFilters() {
+  public function dynamicSegmentFilters() {
     return $this->has_many(__NAMESPACE__ . '\DynamicSegmentFilter', 'segment_id');
   }
 
-  static function findAll() {
+  public static function findAll() {
     $query = self::select('*');
     return $query->where('type', DynamicSegment::TYPE_DYNAMIC)
       ->whereNull('deleted_at')
       ->findMany();
   }
 
-  static function listingQuery(array $data = []) {
+  public static function listingQuery(array $data = []) {
     $query = self::select('*');
     $query->where('type', DynamicSegment::TYPE_DYNAMIC);
     if (isset($data['group'])) {
@@ -62,7 +62,7 @@ class DynamicSegment extends MailPoetSegment {
     return $query;
   }
 
-  static function groups() {
+  public static function groups() {
     return [
       [
         'name' => 'all',
@@ -77,12 +77,12 @@ class DynamicSegment extends MailPoetSegment {
     ];
   }
 
-  function delete() {
+  public function delete() {
     DynamicSegmentFilter::where('segment_id', $this->id)->deleteMany();
     return parent::delete();
   }
 
-  static function bulkTrash($orm) {
+  public static function bulkTrash($orm) {
     $count = parent::bulkAction($orm, function($ids) {
       $placeholders = join(',', array_fill(0, count($ids), '?'));
       DynamicSegment::rawExecute(join(' ', [
@@ -95,7 +95,7 @@ class DynamicSegment extends MailPoetSegment {
     return ['count' => $count];
   }
 
-  static function bulkDelete($orm) {
+  public static function bulkDelete($orm) {
     $count = parent::bulkAction($orm, function($ids) {
       $placeholders = join(',', array_fill(0, count($ids), '?'));
       DynamicSegmentFilter::rawExecute(join(' ', [
diff --git a/lib/Models/DynamicSegmentFilter.php b/lib/Models/DynamicSegmentFilter.php
index 7ed884199a..b0e89ac769 100644
--- a/lib/Models/DynamicSegmentFilter.php
+++ b/lib/Models/DynamicSegmentFilter.php
@@ -13,7 +13,7 @@ class DynamicSegmentFilter extends Model {
 
   public static $_table = MP_DYNAMIC_SEGMENTS_FILTERS_TABLE;
 
-  function save() {
+  public function save() {
     if (is_null($this->filter_data)) {
       $this->filter_data = [];
     }
@@ -25,7 +25,7 @@ class DynamicSegmentFilter extends Model {
     return parent::save();
   }
 
-  static function getAllBySegmentIds($segmentIds) {
+  public static function getAllBySegmentIds($segmentIds) {
     if (empty($segmentIds)) return [];
     $query = self::tableAlias('filters')
       ->whereIn('filters.segment_id', $segmentIds);
@@ -42,7 +42,7 @@ class DynamicSegmentFilter extends Model {
     return $value;
   }
 
-  static function deleteAllBySegmentIds($segmentIds) {
+  public static function deleteAllBySegmentIds($segmentIds) {
     if (empty($segmentIds)) return;
 
     $query = self::tableAlias('filters')
diff --git a/lib/Models/Form.php b/lib/Models/Form.php
index b0e162e8d9..ea59846602 100644
--- a/lib/Models/Form.php
+++ b/lib/Models/Form.php
@@ -14,15 +14,15 @@ use MailPoet\WP\Functions as WPFunctions;
 class Form extends Model {
   public static $_table = MP_FORMS_TABLE;
 
-  function getSettings() {
+  public function getSettings() {
     return WPFunctions::get()->isSerialized($this->settings) ? unserialize($this->settings) : $this->settings;
   }
 
-  function getBody() {
+  public function getBody() {
     return WPFunctions::get()->isSerialized($this->body) ? unserialize($this->body) : $this->body;
   }
 
-  function asArray() {
+  public function asArray() {
     $model = parent::asArray();
 
     $model['body'] = $this->getBody();
@@ -31,7 +31,7 @@ class Form extends Model {
     return $model;
   }
 
-  function save() {
+  public function save() {
     $this->set('body', (is_serialized($this->body))
       ? $this->body
       : serialize($this->body)
@@ -43,7 +43,7 @@ class Form extends Model {
     return parent::save();
   }
 
-  function getFieldList() {
+  public function getFieldList() {
     $body = $this->getBody();
     if (empty($body)) {
       return false;
@@ -69,7 +69,7 @@ class Form extends Model {
     return $fields ?: false;
   }
 
-  function filterSegments(array $segment_ids = []) {
+  public function filterSegments(array $segment_ids = []) {
     $settings = $this->getSettings();
     if (empty($settings['segments'])) {
       return [];
@@ -86,11 +86,11 @@ class Form extends Model {
     return $segment_ids;
   }
 
-  static function search($orm, $search = '') {
+  public static function search($orm, $search = '') {
     return $orm->whereLike('name', '%' . $search . '%');
   }
 
-  static function groups() {
+  public static function groups() {
     return [
       [
         'name' => 'all',
@@ -105,14 +105,14 @@ class Form extends Model {
     ];
   }
 
-  static function groupBy($orm, $group = null) {
+  public static function groupBy($orm, $group = null) {
     if ($group === 'trash') {
       return $orm->whereNotNull('deleted_at');
     }
     return $orm->whereNull('deleted_at');
   }
 
-  static function getDefaultSuccessMessage() {
+  public static function getDefaultSuccessMessage() {
     $settings = SettingsController::getInstance();
     if ($settings->get('signup_confirmation.enabled')) {
       return __('Check your inbox or spam folder to confirm your subscription.', 'mailpoet');
@@ -120,7 +120,7 @@ class Form extends Model {
     return __('You’ve been successfully subscribed to our newsletter!', 'mailpoet');
   }
 
-  static function updateSuccessMessages() {
+  public static function updateSuccessMessages() {
     $right_message = self::getDefaultSuccessMessage();
     $wrong_message = (
       $right_message === __('Check your inbox or spam folder to confirm your subscription.', 'mailpoet')
diff --git a/lib/Models/MappingToExternalEntities.php b/lib/Models/MappingToExternalEntities.php
index be7322458b..a21538d24c 100644
--- a/lib/Models/MappingToExternalEntities.php
+++ b/lib/Models/MappingToExternalEntities.php
@@ -5,7 +5,7 @@ namespace MailPoet\Models;
 class MappingToExternalEntities extends Model {
   public static $_table = MP_MAPPING_TO_EXTERNAL_ENTITIES_TABLE;
 
-  static function create($data = []) {
+  public static function create($data = []) {
     $relation = parent::create();
     $relation->hydrate($data);
     return $relation->save();
diff --git a/lib/Models/Model.php b/lib/Models/Model.php
index d9881ae895..c9e9154585 100644
--- a/lib/Models/Model.php
+++ b/lib/Models/Model.php
@@ -131,7 +131,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
   protected $_errors;
   protected $_new_record;
 
-  function __construct() {
+  public function __construct() {
     $this->_errors = [];
     $validator = new ModelValidator();
     parent::__construct($validator);
@@ -140,7 +140,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
   /**
    * @return static
    */
-  static function create() {
+  public static function create() {
     $created = parent::create();
     if (is_bool($created)) {
       throw new \Exception('ORM is not initialised');
@@ -194,7 +194,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return self::_createOrUpdate($data);
   }
 
-  function getErrors() {
+  public function getErrors() {
     if (empty($this->_errors)) {
       return false;
     } else {
@@ -202,7 +202,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     }
   }
 
-  function setError($error = '', $error_code = null) {
+  public function setError($error = '', $error_code = null) {
     if (!$error_code) {
       $error_code = count($this->_errors);
     }
@@ -216,7 +216,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     }
   }
 
-  function save() {
+  public function save() {
     $this->setTimestamp();
     $this->_new_record = $this->isNew();
     try {
@@ -247,17 +247,17 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return $this;
   }
 
-  function isNew() {
+  public function isNew() {
     return (isset($this->_new_record)) ?
       $this->_new_record :
       parent::isNew();
   }
 
-  function trash() {
+  public function trash() {
     return $this->set_expr('deleted_at', 'NOW()')->save();
   }
 
-  static function bulkTrash($orm) {
+  public static function bulkTrash($orm) {
     $model = get_called_class();
     $count = self::bulkAction($orm, function($ids) use ($model) {
       $model::rawExecute(join(' ', [
@@ -270,7 +270,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return ['count' => $count];
   }
 
-  static function bulkDelete($orm) {
+  public static function bulkDelete($orm) {
     $model = get_called_class();
     $count = self::bulkAction($orm, function($ids) use ($model) {
       $model::whereIn('id', $ids)->deleteMany();
@@ -279,11 +279,11 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return ['count' => $count];
   }
 
-  function restore() {
+  public function restore() {
     return $this->set_expr('deleted_at', 'NULL')->save();
   }
 
-  static function bulkRestore($orm) {
+  public static function bulkRestore($orm) {
     $model = get_called_class();
     $count = self::bulkAction($orm, function($ids) use ($model) {
       $model::rawExecute(join(' ', [
@@ -296,7 +296,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return ['count' => $count];
   }
 
-  static function bulkAction($orm, $callback = false) {
+  public static function bulkAction($orm, $callback = false) {
     $total = $orm->count();
 
     if ($total === 0) return false;
@@ -319,7 +319,7 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
       ->rowCount();
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $model = get_called_class();
     $model_data = array_merge($this->asArray(), $data);
     unset($model_data['id']);
@@ -336,17 +336,17 @@ class Model extends \MailPoetVendor\Sudzy\ValidModel {
     return $duplicate;
   }
 
-  function setTimestamp() {
+  public function setTimestamp() {
     if ($this->created_at === null) {
       $this->set_expr('created_at', 'NOW()');
     }
   }
 
-  static function getPublished() {
+  public static function getPublished() {
     return static::whereNull('deleted_at');
   }
 
-  static function getTrashed() {
+  public static function getTrashed() {
     return static::whereNotNull('deleted_at');
   }
 
diff --git a/lib/Models/ModelValidator.php b/lib/Models/ModelValidator.php
index 23c28651cc..373442f6b0 100644
--- a/lib/Models/ModelValidator.php
+++ b/lib/Models/ModelValidator.php
@@ -46,7 +46,7 @@ class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
     'www',
   ];
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->validators = [
       'validEmail' => 'validateEmail',
@@ -67,19 +67,19 @@ class ModelValidator extends \MailPoetVendor\Sudzy\Engine {
     }
   }
 
-  function validateEmail($email) {
+  public function validateEmail($email) {
     $permitted_length = (strlen($email) >= self::EMAIL_MIN_LENGTH && strlen($email) <= self::EMAIL_MAX_LENGTH);
     $valid_email = WPFunctions::get()->isEmail($email) !== false && parent::_isEmail($email, null);
     return ($permitted_length && $valid_email);
   }
 
-  function validateNonRoleEmail($email) {
+  public function validateNonRoleEmail($email) {
     if (!$this->validateEmail($email)) return false;
     $first_part = strtolower(substr($email, 0, strpos($email, '@')));
     return array_search($first_part, self::ROLE_EMAILS) === false;
   }
 
-  function validateRenderedNewsletterBody($newsletter_body) {
+  public function validateRenderedNewsletterBody($newsletter_body) {
     if (is_serialized($newsletter_body)) {
       $newsletter_body = unserialize($newsletter_body);
     } else if (Helpers::isJson($newsletter_body)) {
diff --git a/lib/Models/Newsletter.php b/lib/Models/Newsletter.php
index 195a3ee25c..5abedb35bd 100644
--- a/lib/Models/Newsletter.php
+++ b/lib/Models/Newsletter.php
@@ -57,18 +57,18 @@ class Newsletter extends Model {
   // automatic newsletters status
   const STATUS_ACTIVE = NewsletterEntity::STATUS_ACTIVE;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->addValidations('type', [
       'required' => WPFunctions::get()->__('Please specify a type.', 'mailpoet'),
     ]);
   }
 
-  function queue() {
+  public function queue() {
     return $this->hasOne(__NAMESPACE__ . '\SendingQueue', 'newsletter_id', 'id');
   }
 
-  function children() {
+  public function children() {
     return $this->hasMany(
       __NAMESPACE__ . '\Newsletter',
       'parent_id',
@@ -76,7 +76,7 @@ class Newsletter extends Model {
     );
   }
 
-  function parent() {
+  public function parent() {
     return $this->hasOne(
       __NAMESPACE__ . '\Newsletter',
       'id',
@@ -84,7 +84,7 @@ class Newsletter extends Model {
     );
   }
 
-  function segments() {
+  public function segments() {
     return $this->hasManyThrough(
       __NAMESPACE__ . '\Segment',
       __NAMESPACE__ . '\NewsletterSegment',
@@ -93,7 +93,7 @@ class Newsletter extends Model {
     );
   }
 
-  function segmentRelations() {
+  public function segmentRelations() {
     return $this->hasMany(
       __NAMESPACE__ . '\NewsletterSegment',
       'newsletter_id',
@@ -101,7 +101,7 @@ class Newsletter extends Model {
     );
   }
 
-  function options() {
+  public function options() {
     return $this->hasManyThrough(
       __NAMESPACE__ . '\NewsletterOptionField',
       __NAMESPACE__ . '\NewsletterOption',
@@ -110,7 +110,7 @@ class Newsletter extends Model {
     )->select_expr(MP_NEWSLETTER_OPTION_TABLE . '.value');
   }
 
-  function save() {
+  public function save() {
     if (is_string($this->deleted_at) && strlen(trim($this->deleted_at)) === 0) {
       $this->set_expr('deleted_at', 'NULL');
     }
@@ -133,7 +133,7 @@ class Newsletter extends Model {
     return parent::save();
   }
 
-  function trash() {
+  public function trash() {
     // trash queue associations
     $children = $this->children()->select('id')->findArray();
     if ($children) {
@@ -170,7 +170,7 @@ class Newsletter extends Model {
     return parent::trash();
   }
 
-  static function bulkTrash($orm) {
+  public static function bulkTrash($orm) {
     // bulk trash queue and notification history associations
     parent::bulkAction($orm, function($ids) {
       $children = Newsletter::whereIn('parent_id', $ids)->select('id')->findArray();
@@ -209,7 +209,7 @@ class Newsletter extends Model {
     return parent::bulkTrash($orm);
   }
 
-  function delete() {
+  public function delete() {
     // delete queue, notification history and segment associations
     $children = $this->children()->select('id')->findArray();
     if ($children) {
@@ -233,7 +233,7 @@ class Newsletter extends Model {
     return parent::delete();
   }
 
-  static function bulkDelete($orm) {
+  public static function bulkDelete($orm) {
     // bulk delete queue, notification history and segment associations
     parent::bulkAction($orm, function($ids) {
       $children = Newsletter::whereIn('parent_id', $ids)->select('id')->findArray();
@@ -259,7 +259,7 @@ class Newsletter extends Model {
     return parent::bulkDelete($orm);
   }
 
-  function restore() {
+  public function restore() {
     // restore trashed queue and notification history associations
     $children = $this->children()->select('id')->findArray();
     if ($children) {
@@ -300,7 +300,7 @@ class Newsletter extends Model {
     return parent::restore();
   }
 
-  static function bulkRestore($orm) {
+  public static function bulkRestore($orm) {
     // bulk restore trashed queue and notification history associations
     parent::bulkAction($orm, function($ids) {
       $children = Newsletter::whereIn('parent_id', $ids)->select('id')->findArray();
@@ -347,7 +347,7 @@ class Newsletter extends Model {
     return parent::bulkRestore($orm);
   }
 
-  function setStatus($status = null) {
+  public function setStatus($status = null) {
     if ($status === self::STATUS_ACTIVE) {
       if (!$this->body || empty(json_decode($this->body))) {
         $this->setError(
@@ -381,7 +381,7 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $newsletter_data = $this->asArray();
 
     // remove id so that it creates a new record
@@ -450,7 +450,7 @@ class Newsletter extends Model {
     return $duplicate;
   }
 
-  function createNotificationHistory() {
+  public function createNotificationHistory() {
     $newsletter_data = $this->asArray();
 
     // remove id so that it creates a new record
@@ -496,7 +496,7 @@ class Newsletter extends Model {
     return $notification_history;
   }
 
-  function asArray() {
+  public function asArray() {
     $model = parent::asArray();
 
     if (isset($model['body'])) {
@@ -505,7 +505,7 @@ class Newsletter extends Model {
     return $model;
   }
 
-  function withSegments($incl_deleted = false) {
+  public function withSegments($incl_deleted = false) {
     $this->segments = $this->segments()->findArray();
     if ($incl_deleted) {
       $this->withDeletedSegments();
@@ -513,7 +513,7 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function withDeletedSegments() {
+  public function withDeletedSegments() {
     if (!empty($this->segments)) {
       $segment_ids = array_column($this->segments, 'id');
       $links = $this->segmentRelations()
@@ -532,16 +532,16 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function withChildrenCount() {
+  public function withChildrenCount() {
     $this->children_count = $this->children()->count();
     return $this;
   }
 
-  function getQueue($columns = '*') {
+  public function getQueue($columns = '*') {
     return SendingTask::getByNewsletterId($this->id);
   }
 
-  function withSendingQueue() {
+  public function withSendingQueue() {
     $queue = $this->getQueue();
     if ($queue === false) {
       $this->queue = false;
@@ -551,7 +551,7 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function withOptions() {
+  public function withOptions() {
     $options = $this->options()->findArray();
     if (empty($options)) {
       $this->options = [];
@@ -561,7 +561,7 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function withTotalSent() {
+  public function withTotalSent() {
     // total of subscribers who received the email
     $this->total_sent = (int)SendingQueue::findTaskByNewsletterId($this->id)
       ->where('tasks.status', SendingQueue::STATUS_COMPLETED)
@@ -569,25 +569,25 @@ class Newsletter extends Model {
     return $this;
   }
 
-  function withScheduledToBeSent() {
+  public function withScheduledToBeSent() {
     $this->total_scheduled = (int)SendingQueue::findTaskByNewsletterId($this->id)
       ->where('tasks.status', SendingQueue::STATUS_SCHEDULED)
       ->count();
     return $this;
   }
 
-  function withStatistics(WCHelper $woocommerce_helper) {
+  public function withStatistics(WCHelper $woocommerce_helper) {
     $statistics = $this->getStatistics($woocommerce_helper);
     $this->statistics = $statistics;
     return $this;
   }
 
-  function render() {
+  public function render() {
     $renderer = new Renderer($this);
     return $renderer->render();
   }
 
-  function getStatistics(WCHelper $woocommerce_helper) {
+  public function getStatistics(WCHelper $woocommerce_helper) {
     if (($this->type !== self::TYPE_WELCOME) && ($this->queue === false)) {
       return false;
     }
@@ -630,7 +630,7 @@ class Newsletter extends Model {
     return $result;
   }
 
-  function wasScheduledForSubscriber($subscriber_id) {
+  public function wasScheduledForSubscriber($subscriber_id) {
     /** @var \stdClass */
     $queue = SendingQueue::rawQuery(
       "SELECT COUNT(*) as count
@@ -645,7 +645,7 @@ class Newsletter extends Model {
   }
 
 
-  static function getAnalytics() {
+  public static function getAnalytics() {
     $welcome_newsletters_count = Newsletter::getPublished()
       ->filter('filterType', self::TYPE_WELCOME)
       ->filter('filterStatus', self::STATUS_ACTIVE)
@@ -703,7 +703,7 @@ class Newsletter extends Model {
     ];
   }
 
-  static function sentAfter($date) {
+  public static function sentAfter($date) {
     return static::tableAlias('newsletters')
       ->where('newsletters.type', self::TYPE_STANDARD)
       ->where('newsletters.status', self::STATUS_SENT)
@@ -722,14 +722,14 @@ class Newsletter extends Model {
       ->count();
   }
 
-  static function search($orm, $search = '') {
+  public static function search($orm, $search = '') {
     if (strlen(trim($search)) > 0) {
       $orm->whereLike('subject', '%' . $search . '%');
     }
     return $orm;
   }
 
-  static function filters($data = []) {
+  public static function filters($data = []) {
     $type = isset($data['params']['type']) ? $data['params']['type'] : null;
     $group = (isset($data['params']['group'])) ? $data['params']['group'] : null;
 
@@ -769,7 +769,7 @@ class Newsletter extends Model {
     return $filters;
   }
 
-  static function filterBy($orm, $data = []) {
+  public static function filterBy($orm, $data = []) {
     // apply filters
     if (!empty($data['filter'])) {
       foreach ($data['filter'] as $key => $value) {
@@ -800,7 +800,7 @@ class Newsletter extends Model {
     return $orm;
   }
 
-  static function filterWithOptions($orm, $type) {
+  public static function filterWithOptions($orm, $type) {
     $orm = $orm->select(MP_NEWSLETTERS_TABLE . '.*');
     $optionFields = NewsletterOptionField::findArray();
     foreach ($optionFields as $optionField) {
@@ -833,7 +833,7 @@ class Newsletter extends Model {
     return $orm;
   }
 
-  static function groups($data = []) {
+  public static function groups($data = []) {
     $type = isset($data['params']['type']) ? $data['params']['type'] : null;
     $group = (isset($data['params']['group'])) ? $data['params']['group'] : null;
     $parentId = (isset($data['params']['parent_id'])) ? $data['params']['parent_id'] : null;
@@ -952,7 +952,7 @@ class Newsletter extends Model {
     return $groups;
   }
 
-  static function groupBy($orm, $data = []) {
+  public static function groupBy($orm, $data = []) {
     $group = (!empty($data['group'])) ? $data['group'] : 'all';
 
     switch ($group) {
@@ -976,7 +976,7 @@ class Newsletter extends Model {
     return $orm;
   }
 
-  static function filterStatus($orm, $status = false) {
+  public static function filterStatus($orm, $status = false) {
     if (in_array($status, [
       self::STATUS_DRAFT,
       self::STATUS_SCHEDULED,
@@ -989,7 +989,7 @@ class Newsletter extends Model {
     return $orm;
   }
 
-  static function filterType($orm, $type = false, $group = false) {
+  public static function filterType($orm, $type = false, $group = false) {
     if (in_array($type, [
       self::TYPE_STANDARD,
       self::TYPE_WELCOME,
@@ -1020,7 +1020,7 @@ class Newsletter extends Model {
     return $orm;
   }
 
-  static function listingQuery($data = []) {
+  public static function listingQuery($data = []) {
     $query = self::select(
       [
         self::$_table . '.id',
@@ -1042,7 +1042,7 @@ class Newsletter extends Model {
       ->filter('search', $data['search']);
   }
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     $data['unsubscribe_token'] = Security::generateUnsubscribeToken(self::class);
     return parent::_createOrUpdate($data, false, function($data) {
       $settings = SettingsController::getInstance();
@@ -1080,7 +1080,7 @@ class Newsletter extends Model {
     });
   }
 
-  static function getWelcomeNotificationsForSegments($segments) {
+  public static function getWelcomeNotificationsForSegments($segments) {
     return NewsletterOption::tableAlias('options')
       ->select('options.newsletter_id')
       ->select('options.value', 'segment_id')
@@ -1101,7 +1101,7 @@ class Newsletter extends Model {
       ->findMany();
   }
 
-  static function getArchives($segment_ids = []) {
+  public static function getArchives($segment_ids = []) {
     $orm = self::tableAlias('newsletters')
       ->distinct()->select('newsletters.*')
       ->select('newsletter_rendered_subject')
@@ -1136,18 +1136,18 @@ class Newsletter extends Model {
     return $orm->findMany();
   }
 
-  static function getByHash($hash) {
+  public static function getByHash($hash) {
     return parent::where('hash', $hash)
       ->findOne();
   }
 
-  function getMeta() {
+  public function getMeta() {
     if (!$this->meta) return;
 
     return (Helpers::isJson($this->meta)) ? json_decode($this->meta, true) : $this->meta;
   }
 
-  static function findOneWithOptions($id) {
+  public static function findOneWithOptions($id) {
     $newsletter = self::findOne($id);
     if (!$newsletter instanceof self) {
       return false;
diff --git a/lib/Models/NewsletterOption.php b/lib/Models/NewsletterOption.php
index e5f1d2ce17..93689cbe23 100644
--- a/lib/Models/NewsletterOption.php
+++ b/lib/Models/NewsletterOption.php
@@ -11,7 +11,7 @@ namespace MailPoet\Models;
 class NewsletterOption extends Model {
   public static $_table = MP_NEWSLETTER_OPTION_TABLE;
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     if (!is_array($data) || empty($data['newsletter_id']) || empty($data['option_field_id'])) {
       return;
     }
diff --git a/lib/Models/NewsletterOptionField.php b/lib/Models/NewsletterOptionField.php
index 676b61a211..7ea5734683 100644
--- a/lib/Models/NewsletterOptionField.php
+++ b/lib/Models/NewsletterOptionField.php
@@ -7,7 +7,7 @@ use MailPoet\WP\Functions as WPFunctions;
 class NewsletterOptionField extends Model {
   public static $_table = MP_NEWSLETTER_OPTION_FIELDS_TABLE;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->addValidations('name', [
       'required' => WPFunctions::get()->__('Please specify a name.', 'mailpoet'),
@@ -17,7 +17,7 @@ class NewsletterOptionField extends Model {
     ]);
   }
 
-  function newsletters() {
+  public function newsletters() {
     return $this->has_many_through(
       __NAMESPACE__ . '\Newsletter',
       __NAMESPACE__ . '\NewsletterOption',
diff --git a/lib/Models/NewsletterPost.php b/lib/Models/NewsletterPost.php
index ba434930d8..b2e9cc5362 100644
--- a/lib/Models/NewsletterPost.php
+++ b/lib/Models/NewsletterPost.php
@@ -10,7 +10,7 @@ namespace MailPoet\Models;
 class NewsletterPost extends Model {
   public static $_table = MP_NEWSLETTER_POSTS_TABLE;
 
-  static function getNewestNewsletterPost($newsletter_id) {
+  public static function getNewestNewsletterPost($newsletter_id) {
     return self::where('newsletter_id', $newsletter_id)
       ->orderByDesc('created_at')
       ->findOne();
diff --git a/lib/Models/NewsletterTemplate.php b/lib/Models/NewsletterTemplate.php
index b3455f9d72..8757b714de 100644
--- a/lib/Models/NewsletterTemplate.php
+++ b/lib/Models/NewsletterTemplate.php
@@ -19,7 +19,7 @@ class NewsletterTemplate extends Model {
   const RECENTLY_SENT_CATEGORIES = '["recent"]';
   const RECENTLY_SENT_COUNT = 12;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
 
     $this->addValidations('name', [
@@ -30,7 +30,7 @@ class NewsletterTemplate extends Model {
     ]);
   }
 
-  static function cleanRecentlySent($data) {
+  public static function cleanRecentlySent($data) {
     if (!empty($data['categories']) && $data['categories'] === self::RECENTLY_SENT_CATEGORIES) {
       $ids = parent::where('categories', self::RECENTLY_SENT_CATEGORIES)
         ->select('id')
@@ -46,7 +46,7 @@ class NewsletterTemplate extends Model {
     }
   }
 
-  function asArray() {
+  public function asArray() {
     $template = parent::asArray();
     if (isset($template['body'])) {
       $template['body'] = json_decode($template['body'], true);
diff --git a/lib/Models/ScheduledTask.php b/lib/Models/ScheduledTask.php
index 28d42e4328..ead697f5f2 100644
--- a/lib/Models/ScheduledTask.php
+++ b/lib/Models/ScheduledTask.php
@@ -34,12 +34,12 @@ class ScheduledTask extends Model {
 
   private $wp;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->wp = new WPFunctions();
   }
 
-  function subscribers() {
+  public function subscribers() {
     return $this->hasManyThrough(
       __NAMESPACE__ . '\Subscriber',
       __NAMESPACE__ . '\ScheduledTaskSubscriber',
@@ -48,13 +48,13 @@ class ScheduledTask extends Model {
     );
   }
 
-  function pause() {
+  public function pause() {
     $this->set('status', self::STATUS_PAUSED);
     $this->save();
     return ($this->getErrors() === false && $this->id() > 0);
   }
 
-  static function pauseAllByNewsletter(Newsletter $newsletter) {
+  public static function pauseAllByNewsletter(Newsletter $newsletter) {
     ScheduledTask::rawExecute(
       'UPDATE `' . ScheduledTask::$_table . '` t ' .
       'JOIN `' . SendingQueue::$_table . '` q ON t.`id` = q.`task_id` ' .
@@ -65,13 +65,13 @@ class ScheduledTask extends Model {
     );
   }
 
-  function resume() {
+  public function resume() {
     $this->setExpr('status', 'NULL');
     $this->save();
     return ($this->getErrors() === false && $this->id() > 0);
   }
 
-  static function setScheduledAllByNewsletter(Newsletter $newsletter) {
+  public static function setScheduledAllByNewsletter(Newsletter $newsletter) {
     ScheduledTask::rawExecute(
       'UPDATE `' . ScheduledTask::$_table . '` t ' .
       'JOIN `' . SendingQueue::$_table . '` q ON t.`id` = q.`task_id` ' .
@@ -83,14 +83,14 @@ class ScheduledTask extends Model {
     );
   }
 
-  function complete() {
+  public function complete() {
     $this->processed_at = $this->wp->currentTime('mysql');
     $this->set('status', self::STATUS_COMPLETED);
     $this->save();
     return ($this->getErrors() === false && $this->id() > 0);
   }
 
-  function save() {
+  public function save() {
     // set the default priority to medium
     if (!$this->priority) {
       $this->priority = self::PRIORITY_MEDIUM;
@@ -105,18 +105,18 @@ class ScheduledTask extends Model {
     return $this;
   }
 
-  function asArray() {
+  public function asArray() {
     $model = parent::asArray();
     $model['meta'] = $this->getMeta();
     return $model;
   }
 
-  function getMeta() {
+  public function getMeta() {
     $meta = (Helpers::isJson($this->meta)) ? json_decode($this->meta, true) : $this->meta;
     return !empty($meta) ? (array)$meta : [];
   }
 
-  function delete() {
+  public function delete() {
     try {
       ORM::get_db()->beginTransaction();
       ScheduledTaskSubscriber::where('task_id', $this->id)->deleteMany();
@@ -129,7 +129,7 @@ class ScheduledTask extends Model {
     return null;
   }
 
-  function rescheduleProgressively() {
+  public function rescheduleProgressively() {
     $scheduled_at = Carbon::createFromTimestamp($this->wp->currentTime('timestamp'));
     $timeout = (int)min(self::BASIC_RESCHEDULE_TIMEOUT * pow(2, $this->reschedule_count), self::MAX_RESCHEDULE_TIMEOUT);
     $this->scheduled_at = $scheduled_at->addMinutes($timeout);
@@ -139,7 +139,7 @@ class ScheduledTask extends Model {
     return $timeout;
   }
 
-  static function touchAllByIds(array $ids) {
+  public static function touchAllByIds(array $ids) {
     ScheduledTask::rawExecute(
       'UPDATE `' . ScheduledTask::$_table . '`' .
       'SET `updated_at` = NOW() ' .
@@ -150,7 +150,7 @@ class ScheduledTask extends Model {
   /**
    * @return ScheduledTask|null
    */
-  static function findOneScheduledByNewsletterIdAndSubscriberId($newsletter_id, $subscriber_id) {
+  public static function findOneScheduledByNewsletterIdAndSubscriberId($newsletter_id, $subscriber_id) {
     return ScheduledTask::tableAlias('tasks')
       ->select('tasks.*')
       ->innerJoin(SendingQueue::$_table, 'queues.task_id = tasks.id', 'queues')
@@ -163,19 +163,19 @@ class ScheduledTask extends Model {
       ->findOne() ?: null;
   }
 
-  static function findDueByType($type, $limit = null) {
+  public static function findDueByType($type, $limit = null) {
     return self::findByTypeAndStatus($type, ScheduledTask::STATUS_SCHEDULED, $limit);
   }
 
-  static function findRunningByType($type, $limit = null) {
+  public static function findRunningByType($type, $limit = null) {
     return self::findByTypeAndStatus($type, null, $limit);
   }
 
-  static function findFutureScheduledByType($type, $limit = null) {
+  public static function findFutureScheduledByType($type, $limit = null) {
     return self::findByTypeAndStatus($type, ScheduledTask::STATUS_SCHEDULED, $limit, true);
   }
 
-  static function findCompletedByType($type, $limit = null) {
+  public static function findCompletedByType($type, $limit = null) {
     return self::findByTypeAndStatus($type, ScheduledTask::STATUS_COMPLETED, $limit);
   }
 
diff --git a/lib/Models/ScheduledTaskSubscriber.php b/lib/Models/ScheduledTaskSubscriber.php
index 21b4f78c3b..5c40f74279 100644
--- a/lib/Models/ScheduledTaskSubscriber.php
+++ b/lib/Models/ScheduledTaskSubscriber.php
@@ -25,11 +25,11 @@ class ScheduledTaskSubscriber extends Model {
   public static $_table = MP_SCHEDULED_TASK_SUBSCRIBERS_TABLE;
   public static $_id_column = ['task_id', 'subscriber_id'];
 
-  function task() {
+  public function task() {
     return $this->hasOne(__NAMESPACE__ . '\ScheduledTask', 'id', 'task_id');
   }
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     if (!is_array($data) || empty($data['task_id']) || empty($data['subscriber_id'])) {
       return;
     }
@@ -41,7 +41,7 @@ class ScheduledTaskSubscriber extends Model {
     ]);
   }
 
-  static function setSubscribers($task_id, array $subscriber_ids) {
+  public static function setSubscribers($task_id, array $subscriber_ids) {
     static::clearSubscribers($task_id);
     return static::addSubscribers($task_id, $subscriber_ids);
   }
@@ -49,7 +49,7 @@ class ScheduledTaskSubscriber extends Model {
   /**
    * For large batches use MailPoet\Segments\SubscribersFinder::addSubscribersToTaskFromSegments()
    */
-  static function addSubscribers($task_id, array $subscriber_ids) {
+  public static function addSubscribers($task_id, array $subscriber_ids) {
     foreach ($subscriber_ids as $subscriber_id) {
       self::createOrUpdate([
         'task_id' => $task_id,
@@ -58,23 +58,23 @@ class ScheduledTaskSubscriber extends Model {
     }
   }
 
-  static function clearSubscribers($task_id) {
+  public static function clearSubscribers($task_id) {
     return self::where('task_id', $task_id)->deleteMany();
   }
 
-  static function getUnprocessedCount($task_id) {
+  public static function getUnprocessedCount($task_id) {
     return self::getCount($task_id, self::STATUS_UNPROCESSED);
   }
 
-  static function getProcessedCount($task_id) {
+  public static function getProcessedCount($task_id) {
     return self::getCount($task_id, self::STATUS_PROCESSED);
   }
 
-  static function getTotalCount($task_id) {
+  public static function getTotalCount($task_id) {
     return self::getCount($task_id);
   }
 
-  static function listingQuery($data) {
+  public static function listingQuery($data) {
     $group = isset($data['group']) ? $data['group'] : 'all';
     return self::join(Subscriber::$_table, ["subscriber_id", "=", "subscribers.id"], "subscribers")
       ->filter($group, $data['params'])
@@ -88,7 +88,7 @@ class ScheduledTaskSubscriber extends Model {
       ->select('subscribers.first_name', 'firstName');
   }
 
-  static function groups($data) {
+  public static function groups($data) {
     $params = $data['params'];
     return [
       [
@@ -114,23 +114,23 @@ class ScheduledTaskSubscriber extends Model {
     ];
   }
 
-  static function all($orm, $params) {
+  public static function all($orm, $params) {
     return $orm->whereIn('task_id', $params['task_ids']);
   }
 
-  static function sent($orm, $params) {
+  public static function sent($orm, $params) {
     return $orm->filter('all', $params)
       ->where('processed', self::STATUS_PROCESSED)
       ->where('failed', self::FAIL_STATUS_OK);
   }
 
-  static function failed($orm, $params) {
+  public static function failed($orm, $params) {
     return $orm->filter('all', $params)
       ->where('processed', self::STATUS_PROCESSED)
       ->where('failed', self::FAIL_STATUS_FAILED);
   }
 
-  static function unprocessed($orm, $params) {
+  public static function unprocessed($orm, $params) {
     return $orm->filter('all', $params)
       ->where('processed', self::STATUS_UNPROCESSED);
   }
diff --git a/lib/Models/Segment.php b/lib/Models/Segment.php
index 08c8ad84dc..b54012fe71 100644
--- a/lib/Models/Segment.php
+++ b/lib/Models/Segment.php
@@ -21,7 +21,7 @@ class Segment extends Model {
   const TYPE_WC_USERS = SegmentEntity::TYPE_WC_USERS;
   const TYPE_DEFAULT = SegmentEntity::TYPE_DEFAULT;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
 
     $this->addValidations('name', [
@@ -29,13 +29,13 @@ class Segment extends Model {
     ]);
   }
 
-  function delete() {
+  public function delete() {
     // delete all relations to subscribers
     SubscriberSegment::where('segment_id', $this->id)->deleteMany();
     return parent::delete();
   }
 
-  function newsletters() {
+  public function newsletters() {
     return $this->has_many_through(
       __NAMESPACE__ . '\Newsletter',
       __NAMESPACE__ . '\NewsletterSegment',
@@ -44,7 +44,7 @@ class Segment extends Model {
     );
   }
 
-  function subscribers() {
+  public function subscribers() {
     return $this->has_many_through(
       __NAMESPACE__ . '\Subscriber',
       __NAMESPACE__ . '\SubscriberSegment',
@@ -53,7 +53,7 @@ class Segment extends Model {
     );
   }
 
-  function duplicate($data = []) {
+  public function duplicate($data = []) {
     $duplicate = parent::duplicate($data);
 
     if ($duplicate !== false) {
@@ -69,20 +69,20 @@ class Segment extends Model {
     return false;
   }
 
-  function addSubscriber($subscriber_id) {
+  public function addSubscriber($subscriber_id) {
     $relation = SubscriberSegment::create();
     $relation->set('subscriber_id', $subscriber_id);
     $relation->set('segment_id', $this->id);
     return $relation->save();
   }
 
-  function removeSubscriber($subscriber_id) {
+  public function removeSubscriber($subscriber_id) {
     return SubscriberSegment::where('subscriber_id', $subscriber_id)
       ->where('segment_id', $this->id)
       ->delete();
   }
 
-  function withSubscribersCount() {
+  public function withSubscribersCount() {
     $this->subscribers_count = SubscriberSegment::tableAlias('relation')
       ->where('relation.segment_id', $this->id)
       ->join(
@@ -122,7 +122,7 @@ class Segment extends Model {
     return $this;
   }
 
-  function withAutomatedEmailsSubjects() {
+  public function withAutomatedEmailsSubjects() {
     $automated_emails = NewsletterSegment::tableAlias('relation')
       ->where('relation.segment_id', $this->id)
       ->join(
@@ -145,7 +145,7 @@ class Segment extends Model {
     return $this;
   }
 
-  static function getWPSegment() {
+  public static function getWPSegment() {
     $wp_segment = self::where('type', self::TYPE_WP_USERS)->findOne();
 
     if ($wp_segment === false) {
@@ -163,7 +163,7 @@ class Segment extends Model {
     return $wp_segment;
   }
 
-  static function getWooCommerceSegment() {
+  public static function getWooCommerceSegment() {
     $wc_segment = self::where('type', self::TYPE_WC_USERS)->findOne();
 
     if ($wc_segment === false) {
@@ -181,7 +181,7 @@ class Segment extends Model {
     return $wc_segment;
   }
 
-  static function shouldShowWooCommerceSegment() {
+  public static function shouldShowWooCommerceSegment() {
     $woocommerce_helper = new WCHelper();
     $is_woocommerce_active = $woocommerce_helper->isWooCommerceActive();
     $woocommerce_user_exists = Segment::tableAlias('segment')
@@ -200,7 +200,7 @@ class Segment extends Model {
     return true;
   }
 
-  static function getSegmentTypes() {
+  public static function getSegmentTypes() {
     $types = [Segment::TYPE_DEFAULT, Segment::TYPE_WP_USERS];
     if (Segment::shouldShowWooCommerceSegment()) {
       $types[] = Segment::TYPE_WC_USERS;
@@ -208,11 +208,11 @@ class Segment extends Model {
     return $types;
   }
 
-  static function search($orm, $search = '') {
+  public static function search($orm, $search = '') {
     return $orm->whereLike('name', '%' . $search . '%');
   }
 
-  static function groups() {
+  public static function groups() {
     $all_query = Segment::getPublished();
     if (!Segment::shouldShowWooCommerceSegment()) {
       $all_query->whereNotEqual('type', self::TYPE_WC_USERS);
@@ -231,7 +231,7 @@ class Segment extends Model {
     ];
   }
 
-  static function groupBy($orm, $group = null) {
+  public static function groupBy($orm, $group = null) {
     if ($group === 'trash') {
       $orm->whereNotNull('deleted_at');
     } else {
@@ -240,7 +240,7 @@ class Segment extends Model {
     return $orm;
   }
 
-  static function getSegmentsWithSubscriberCount($type = self::TYPE_DEFAULT) {
+  public static function getSegmentsWithSubscriberCount($type = self::TYPE_DEFAULT) {
     $query = self::selectMany([self::$_table . '.id', self::$_table . '.name'])
       ->whereIn('type', Segment::getSegmentTypes())
       ->selectExpr(
@@ -271,14 +271,14 @@ class Segment extends Model {
     return $query->findArray();
   }
 
-  static function getSegmentsForImport() {
+  public static function getSegmentsForImport() {
     $segments = self::getSegmentsWithSubscriberCount($type = false);
     return array_values(array_filter($segments, function($segment) {
       return $segment['type'] !== Segment::TYPE_WC_USERS;
     }));
   }
 
-  static function getSegmentsForExport() {
+  public static function getSegmentsForExport() {
     return self::rawQuery(
       '(SELECT segments.id, segments.name, COUNT(relation.subscriber_id) as subscribers ' .
       'FROM ' . MP_SUBSCRIBER_SEGMENT_TABLE . ' relation ' .
@@ -298,7 +298,7 @@ class Segment extends Model {
     )->findArray();
   }
 
-  static function listingQuery(array $data = []) {
+  public static function listingQuery(array $data = []) {
     $query = self::select('*');
     $query->whereIn('type', Segment::getSegmentTypes());
     if (isset($data['group'])) {
@@ -307,11 +307,11 @@ class Segment extends Model {
     return $query;
   }
 
-  static function getPublic() {
+  public static function getPublic() {
     return self::getPublished()->where('type', self::TYPE_DEFAULT)->orderByAsc('name');
   }
 
-  static function bulkTrash($orm) {
+  public static function bulkTrash($orm) {
     $count = parent::bulkAction($orm, function($ids) {
       Segment::rawExecute(join(' ', [
         'UPDATE `' . Segment::$_table . '`',
@@ -324,7 +324,7 @@ class Segment extends Model {
     return ['count' => $count];
   }
 
-  static function bulkDelete($orm) {
+  public static function bulkDelete($orm) {
     $count = parent::bulkAction($orm, function($ids) {
       // delete segments (only default)
       $segments = Segment::whereIn('id', $ids)
@@ -341,7 +341,7 @@ class Segment extends Model {
     return ['count' => $count];
   }
 
-  static function getAnalytics() {
+  public static function getAnalytics() {
     $analytics = Segment::selectExpr('type, count(*) as count')
                         ->whereNull('deleted_at')
                         ->groupBy('type')
diff --git a/lib/Models/SendingQueue.php b/lib/Models/SendingQueue.php
index 71dafa5d72..156eefe40b 100644
--- a/lib/Models/SendingQueue.php
+++ b/lib/Models/SendingQueue.php
@@ -30,7 +30,7 @@ class SendingQueue extends Model {
   const PRIORITY_MEDIUM = SendingQueueEntity::PRIORITY_MEDIUM;
   const PRIORITY_LOW = SendingQueueEntity::PRIORITY_LOW;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
 
     $this->addValidations('newsletter_rendered_body', [
@@ -38,15 +38,15 @@ class SendingQueue extends Model {
     ]);
   }
 
-  function task() {
+  public function task() {
     return $this->hasOne(__NAMESPACE__ . '\ScheduledTask', 'id', 'task_id');
   }
 
-  function newsletter() {
+  public function newsletter() {
     return $this->has_one(__NAMESPACE__ . '\Newsletter', 'id', 'newsletter_id');
   }
 
-  function pause() {
+  public function pause() {
     if ($this->count_processed === $this->count_total) {
       return false;
     } else {
@@ -54,7 +54,7 @@ class SendingQueue extends Model {
     }
   }
 
-  function resume() {
+  public function resume() {
     if ($this->count_processed === $this->count_total) {
       return $this->complete();
     } else {
@@ -62,11 +62,11 @@ class SendingQueue extends Model {
     }
   }
 
-  function complete() {
+  public function complete() {
     return $this->task()->findOne()->complete();
   }
 
-  function save() {
+  public function save() {
     $this->newsletter_rendered_body = $this->getNewsletterRenderedBody();
     if (!Helpers::isJson($this->newsletter_rendered_body) && !is_null($this->newsletter_rendered_body)) {
       $this->set(
@@ -99,18 +99,18 @@ class SendingQueue extends Model {
     return $subscribers;
   }
 
-  function getNewsletterRenderedBody($type = false) {
+  public function getNewsletterRenderedBody($type = false) {
     $rendered_newsletter = $this->decodeRenderedNewsletterBodyObject($this->newsletter_rendered_body);
     return ($type && !empty($rendered_newsletter[$type])) ?
       $rendered_newsletter[$type] :
       $rendered_newsletter;
   }
 
-  function getMeta() {
+  public function getMeta() {
     return (Helpers::isJson($this->meta)) ? json_decode($this->meta, true) : $this->meta;
   }
 
-  function isSubscriberProcessed($subscriber_id) {
+  public function isSubscriberProcessed($subscriber_id) {
     if (!empty($this->subscribers)
       && ScheduledTaskSubscriber::getTotalCount($this->task_id) === 0
     ) {
@@ -126,7 +126,7 @@ class SendingQueue extends Model {
     }
   }
 
-  function asArray() {
+  public function asArray() {
     $model = parent::asArray();
     $model['newsletter_rendered_body'] = $this->getNewsletterRenderedBody();
     $model['meta'] = $this->getMeta();
@@ -143,7 +143,7 @@ class SendingQueue extends Model {
     return $rendered_body;
   }
 
-  static function getTasks() {
+  public static function getTasks() {
     return ScheduledTask::tableAlias('tasks')
     ->selectExpr('tasks.*')
     ->join(
@@ -153,7 +153,7 @@ class SendingQueue extends Model {
     );
   }
 
-  static function joinWithTasks() {
+  public static function joinWithTasks() {
     return static::tableAlias('queues')
     ->join(
       MP_SCHEDULED_TASKS_TABLE,
@@ -162,7 +162,7 @@ class SendingQueue extends Model {
     );
   }
 
-  static function joinWithSubscribers() {
+  public static function joinWithSubscribers() {
     return static::joinWithTasks()
     ->join(
       MP_SCHEDULED_TASK_SUBSCRIBERS_TABLE,
@@ -171,7 +171,7 @@ class SendingQueue extends Model {
     );
   }
 
-  static function findTaskByNewsletterId($newsletter_id) {
+  public static function findTaskByNewsletterId($newsletter_id) {
     return static::getTasks()
     ->where('queues.newsletter_id', $newsletter_id);
   }
diff --git a/lib/Models/StatisticsClicks.php b/lib/Models/StatisticsClicks.php
index a592978f68..0161e24147 100644
--- a/lib/Models/StatisticsClicks.php
+++ b/lib/Models/StatisticsClicks.php
@@ -14,7 +14,7 @@ use DateTimeInterface;
 class StatisticsClicks extends Model {
   public static $_table = MP_STATISTICS_CLICKS_TABLE;
 
-  static function createOrUpdateClickCount($link_id, $subscriber_id, $newsletter_id, $queue_id) {
+  public static function createOrUpdateClickCount($link_id, $subscriber_id, $newsletter_id, $queue_id) {
     $statistics = self::where('link_id', $link_id)
       ->where('subscriber_id', $subscriber_id)
       ->where('newsletter_id', $newsletter_id)
@@ -33,7 +33,7 @@ class StatisticsClicks extends Model {
     return $statistics->save();
   }
 
-  static function getAllForSubscriber(Subscriber $subscriber) {
+  public static function getAllForSubscriber(Subscriber $subscriber) {
     return static::tableAlias('clicks')
       ->select('clicks.id', 'id')
       ->select('newsletter_rendered_subject')
@@ -53,7 +53,7 @@ class StatisticsClicks extends Model {
       ->orderByAsc('url');
   }
 
-  static function findLatestPerNewsletterBySubscriber(Subscriber $subscriber, DateTimeInterface $from, DateTimeInterface $to) {
+  public static function findLatestPerNewsletterBySubscriber(Subscriber $subscriber, DateTimeInterface $from, DateTimeInterface $to) {
     // subquery to find latest click IDs for each newsletter
     $table = self::$_table;
     $latest_click_ids_per_newsletter_query = "
diff --git a/lib/Models/StatisticsNewsletters.php b/lib/Models/StatisticsNewsletters.php
index 8ec10fd8c3..790e8dc733 100644
--- a/lib/Models/StatisticsNewsletters.php
+++ b/lib/Models/StatisticsNewsletters.php
@@ -8,7 +8,7 @@ namespace MailPoet\Models;
 class StatisticsNewsletters extends Model {
   public static $_table = MP_STATISTICS_NEWSLETTERS_TABLE;
 
-  static function createMultiple(array $data) {
+  public static function createMultiple(array $data) {
     $values = [];
     foreach ($data as $value) {
       if (!empty($value['newsletter_id']) &&
@@ -32,7 +32,7 @@ class StatisticsNewsletters extends Model {
     );
   }
 
-  static function getAllForSubscriber(Subscriber $subscriber) {
+  public static function getAllForSubscriber(Subscriber $subscriber) {
     return static::tableAlias('statistics')
       ->select('statistics.newsletter_id', 'newsletter_id')
       ->select('newsletter_rendered_subject')
diff --git a/lib/Models/StatisticsOpens.php b/lib/Models/StatisticsOpens.php
index 600cc25b0f..50a3e9da93 100644
--- a/lib/Models/StatisticsOpens.php
+++ b/lib/Models/StatisticsOpens.php
@@ -10,7 +10,7 @@ namespace MailPoet\Models;
 class StatisticsOpens extends Model {
   public static $_table = MP_STATISTICS_OPENS_TABLE;
 
-  static function getOrCreate($subscriber_id, $newsletter_id, $queue_id) {
+  public static function getOrCreate($subscriber_id, $newsletter_id, $queue_id) {
     $statistics = self::where('subscriber_id', $subscriber_id)
       ->where('newsletter_id', $newsletter_id)
       ->where('queue_id', $queue_id)
diff --git a/lib/Models/StatisticsUnsubscribes.php b/lib/Models/StatisticsUnsubscribes.php
index 57f3ac7069..c0c916c4e2 100644
--- a/lib/Models/StatisticsUnsubscribes.php
+++ b/lib/Models/StatisticsUnsubscribes.php
@@ -10,7 +10,7 @@ namespace MailPoet\Models;
 class StatisticsUnsubscribes extends Model {
   public static $_table = MP_STATISTICS_UNSUBSCRIBES_TABLE;
 
-  static function getOrCreate($subscriber_id, $newsletter_id, $queue_id) {
+  public static function getOrCreate($subscriber_id, $newsletter_id, $queue_id) {
     $statistics = self::where('subscriber_id', $subscriber_id)
       ->where('newsletter_id', $newsletter_id)
       ->where('queue_id', $queue_id)
diff --git a/lib/Models/StatisticsWooCommercePurchases.php b/lib/Models/StatisticsWooCommercePurchases.php
index 632975dc78..12ad0cdf43 100644
--- a/lib/Models/StatisticsWooCommercePurchases.php
+++ b/lib/Models/StatisticsWooCommercePurchases.php
@@ -16,7 +16,7 @@ use WC_Order;
 class StatisticsWooCommercePurchases extends Model {
   public static $_table = MP_STATISTICS_WOOCOMMERCE_PURCHASES_TABLE;
 
-  static function createOrUpdateByClickDataAndOrder(StatisticsClicks $click, WC_Order $order) {
+  public static function createOrUpdateByClickDataAndOrder(StatisticsClicks $click, WC_Order $order) {
     // search by subscriber and newsletter IDs (instead of click itself) to avoid duplicities
     // when a new click from the subscriber appeared since last tracking for given newsletter
     // (this will keep the originally tracked click - likely the click that led to the order)
diff --git a/lib/Models/Subscriber.php b/lib/Models/Subscriber.php
index 0de4eca92b..fb5a578d2d 100644
--- a/lib/Models/Subscriber.php
+++ b/lib/Models/Subscriber.php
@@ -46,7 +46,7 @@ class Subscriber extends Model {
   /** @var string|bool */
   public $token;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
 
     $this->addValidations('email', [
@@ -55,7 +55,7 @@ class Subscriber extends Model {
     ]);
   }
 
-  static function findOne($id = false) {
+  public static function findOne($id = false) {
     if (is_int($id) || (string)(int)$id === $id) {
       return parent::findOne($id);
     } else if (strlen(trim($id)) > 0) {
@@ -64,7 +64,7 @@ class Subscriber extends Model {
     return false;
   }
 
-  function segments() {
+  public function segments() {
     return $this->has_many_through(
       __NAMESPACE__ . '\Segment',
       __NAMESPACE__ . '\SubscriberSegment',
@@ -74,13 +74,13 @@ class Subscriber extends Model {
     ->where(MP_SUBSCRIBER_SEGMENT_TABLE . '.status', self::STATUS_SUBSCRIBED);
   }
 
-  function save() {
+  public function save() {
     // convert email to lowercase format
     $this->email = strtolower($this->email);
     return parent::save();
   }
 
-  function delete() {
+  public function delete() {
     // WP Users cannot be deleted
     if (!$this->isWPUser() && !$this->isWooCommerceUser()) {
       // delete all relations to segments
@@ -92,7 +92,7 @@ class Subscriber extends Model {
     return null;
   }
 
-  function trash() {
+  public function trash() {
     // WP Users cannot be trashed
     if ($this->isWPUser() || $this->isWooCommerceUser()) {
       return false;
@@ -101,15 +101,15 @@ class Subscriber extends Model {
     }
   }
 
-  function isWPUser() {
+  public function isWPUser() {
     return (bool)$this->wp_user_id;
   }
 
-  function isWooCommerceUser() {
+  public function isWooCommerceUser() {
     return (bool)$this->is_woocommerce_user;
   }
 
-  static function getCurrentWPUser() {
+  public static function getCurrentWPUser() {
     $wp_user = WPFunctions::get()->wpGetCurrentUser();
     if (empty($wp_user->ID)) {
       return false; // Don't look up a subscriber for guests
@@ -117,7 +117,7 @@ class Subscriber extends Model {
     return self::where('wp_user_id', $wp_user->ID)->findOne();
   }
 
-  static function filterOutReservedColumns(array $subscriber_data) {
+  public static function filterOutReservedColumns(array $subscriber_data) {
     $reserved_columns = [
       'id',
       'wp_user_id',
@@ -138,7 +138,7 @@ class Subscriber extends Model {
     return $subscriber_data;
   }
 
-  static function search($orm, $search = '') {
+  public static function search($orm, $search = '') {
     if (strlen(trim($search)) === 0) {
       return $orm;
     }
@@ -149,7 +149,7 @@ class Subscriber extends Model {
     );
   }
 
-  static function filters($data = []) {
+  public static function filters($data = []) {
     $group = (!empty($data['group'])) ? $data['group'] : 'all';
 
     $segments = Segment::orderByAsc('name')
@@ -202,7 +202,7 @@ class Subscriber extends Model {
     return $filters;
   }
 
-  static function filterBy($orm, $filters = null) {
+  public static function filterBy($orm, $filters = null) {
     if (empty($filters)) {
       return $orm;
     }
@@ -221,7 +221,7 @@ class Subscriber extends Model {
     return $orm;
   }
 
-  static function groups() {
+  public static function groups() {
     return [
       [
         'name' => 'all',
@@ -261,7 +261,7 @@ class Subscriber extends Model {
     ];
   }
 
-  static function groupBy($orm, $group = null) {
+  public static function groupBy($orm, $group = null) {
     if ($group === 'trash') {
       return $orm->whereNotNull('deleted_at');
     } else if ($group === 'all') {
@@ -271,7 +271,7 @@ class Subscriber extends Model {
     }
   }
 
-  static function filterWithCustomFields($orm) {
+  public static function filterWithCustomFields($orm) {
     $orm = $orm->select(MP_SUBSCRIBERS_TABLE . '.*');
     $customFields = CustomField::findArray();
     foreach ($customFields as $customField) {
@@ -301,7 +301,7 @@ class Subscriber extends Model {
     return $orm;
   }
 
-  static function filterWithCustomFieldsForExport($orm) {
+  public static function filterWithCustomFieldsForExport($orm) {
     $orm = $orm->select(MP_SUBSCRIBERS_TABLE . '.*');
     $customFields = CustomField::findArray();
     foreach ($customFields as $customField) {
@@ -329,7 +329,7 @@ class Subscriber extends Model {
     return $orm;
   }
 
-  static function getSubscribedInSegments($segment_ids) {
+  public static function getSubscribedInSegments($segment_ids) {
     $subscribers = SubscriberSegment::tableAlias('relation')
       ->whereIn('relation.segment_id', $segment_ids)
       ->where('relation.status', 'subscribed')
@@ -349,7 +349,7 @@ class Subscriber extends Model {
    * @param string $customer_email
    * @return bool|Subscriber
    */
-  static function getWooCommerceSegmentSubscriber($customer_email) {
+  public static function getWooCommerceSegmentSubscriber($customer_email) {
     $wc_segment = Segment::getWooCommerceSegment();
     return Subscriber::tableAlias('subscribers')
       ->select('subscribers.*')
@@ -366,7 +366,7 @@ class Subscriber extends Model {
       ->findOne();
   }
 
-  function customFields() {
+  public function customFields() {
     return $this->hasManyThrough(
       __NAMESPACE__ . '\CustomField',
       __NAMESPACE__ . '\SubscriberCustomField',
@@ -375,7 +375,7 @@ class Subscriber extends Model {
     )->select_expr(MP_SUBSCRIBER_CUSTOM_FIELD_TABLE . '.value');
   }
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     $subscriber = false;
     if (is_array($data) && !empty($data)) {
       $data = WPFunctions::get()->stripslashesDeep($data);
@@ -450,7 +450,7 @@ class Subscriber extends Model {
     return $subscriber;
   }
 
-  function withCustomFields() {
+  public function withCustomFields() {
     $custom_fields = CustomField::select('id')->findArray();
     if (empty($custom_fields)) return $this;
 
@@ -467,18 +467,18 @@ class Subscriber extends Model {
     return $this;
   }
 
-  function withSegments() {
+  public function withSegments() {
     $this->segments = $this->segments()->findArray();
     return $this;
   }
 
-  function withSubscriptions() {
+  public function withSubscriptions() {
     $this->subscriptions = SubscriberSegment::where('subscriber_id', $this->id())
       ->findArray();
     return $this;
   }
 
-  function getCustomField($custom_field_id, $default = null) {
+  public function getCustomField($custom_field_id, $default = null) {
     $custom_field = SubscriberCustomField::select('value')
       ->where('custom_field_id', $custom_field_id)
       ->where('subscriber_id', $this->id())
@@ -491,7 +491,7 @@ class Subscriber extends Model {
     }
   }
 
-  function saveCustomFields($custom_fields_data = []) {
+  public function saveCustomFields($custom_fields_data = []) {
     // get custom field ids
     $custom_field_ids = array_keys($custom_fields_data);
 
@@ -510,7 +510,7 @@ class Subscriber extends Model {
     }
   }
 
-  function setCustomField($custom_field_id, $value) {
+  public function setCustomField($custom_field_id, $value) {
     return SubscriberCustomField::createOrUpdate([
       'subscriber_id' => $this->id(),
       'custom_field_id' => $custom_field_id,
@@ -518,7 +518,7 @@ class Subscriber extends Model {
     ]);
   }
 
-  function setUnconfirmedData(array $subscriber_data) {
+  public function setUnconfirmedData(array $subscriber_data) {
     $subscriber_data = self::filterOutReservedColumns($subscriber_data);
     $encoded = json_encode($subscriber_data);
     if (is_string($encoded)) {
@@ -526,7 +526,7 @@ class Subscriber extends Model {
     }
   }
 
-  function getUnconfirmedData() {
+  public function getUnconfirmedData() {
     if (!empty($this->unconfirmed_data)) {
       $subscriber_data = json_decode($this->unconfirmed_data, true);
       $subscriber_data = self::filterOutReservedColumns((array)$subscriber_data);
@@ -535,7 +535,7 @@ class Subscriber extends Model {
     return null;
   }
 
-  static function bulkAddToList($orm, $data = []) {
+  public static function bulkAddToList($orm, $data = []) {
     $segment_id = (isset($data['segment_id']) ? (int)$data['segment_id'] : 0);
     $segment = Segment::findOne($segment_id);
 
@@ -555,7 +555,7 @@ class Subscriber extends Model {
     ];
   }
 
-  static function bulkMoveToList($orm, $data = []) {
+  public static function bulkMoveToList($orm, $data = []) {
     $segment_id = (isset($data['segment_id']) ? (int)$data['segment_id'] : 0);
     $segment = Segment::findOne($segment_id);
 
@@ -576,7 +576,7 @@ class Subscriber extends Model {
     ];
   }
 
-  static function bulkRemoveFromList($orm, $data = []) {
+  public static function bulkRemoveFromList($orm, $data = []) {
     $segment_id = (isset($data['segment_id']) ? (int)$data['segment_id'] : 0);
     $segment = Segment::findOne($segment_id);
 
@@ -596,7 +596,7 @@ class Subscriber extends Model {
     ];
   }
 
-  static function bulkRemoveFromAllLists($orm, $data = []) {
+  public static function bulkRemoveFromAllLists($orm, $data = []) {
     $count = $orm->count();
 
     parent::bulkAction($orm, function($subscriber_ids) {
@@ -608,7 +608,7 @@ class Subscriber extends Model {
     ];
   }
 
-  static function getTotalSubscribers() {
+  public static function getTotalSubscribers() {
     return self::whereIn('status', [
       self::STATUS_SUBSCRIBED,
       self::STATUS_UNCONFIRMED,
@@ -618,13 +618,13 @@ class Subscriber extends Model {
     ->count();
   }
 
-  static function getInactiveSubscribersCount() {
+  public static function getInactiveSubscribersCount() {
     return self::where('status', self::STATUS_INACTIVE)
     ->whereNull('deleted_at')
     ->count();
   }
 
-  static function bulkTrash($orm) {
+  public static function bulkTrash($orm) {
     $count = parent::bulkAction($orm, function($subscriber_ids) {
       Subscriber::rawExecute(join(' ', [
           'UPDATE `' . Subscriber::$_table . '`',
@@ -642,7 +642,7 @@ class Subscriber extends Model {
     return ['count' => $count];
   }
 
-  static function bulkDelete($orm) {
+  public static function bulkDelete($orm) {
     $count = parent::bulkAction($orm, function($subscriber_ids) {
       // delete all subscriber/segment relationships
       SubscriberSegment::deleteManySubscriptions($subscriber_ids);
@@ -658,37 +658,37 @@ class Subscriber extends Model {
     return ['count' => $count];
   }
 
-  static function subscribed($orm) {
+  public static function subscribed($orm) {
     return $orm
       ->whereNull('deleted_at')
       ->where('status', self::STATUS_SUBSCRIBED);
   }
 
-  static function unsubscribed($orm) {
+  public static function unsubscribed($orm) {
     return $orm
       ->whereNull('deleted_at')
       ->where('status', self::STATUS_UNSUBSCRIBED);
   }
 
-  static function unconfirmed($orm) {
+  public static function unconfirmed($orm) {
     return $orm
       ->whereNull('deleted_at')
       ->where('status', self::STATUS_UNCONFIRMED);
   }
 
-  static function bounced($orm) {
+  public static function bounced($orm) {
     return $orm
       ->whereNull('deleted_at')
       ->where('status', self::STATUS_BOUNCED);
   }
 
-  static function inactive($orm) {
+  public static function inactive($orm) {
     return $orm
       ->whereNull('deleted_at')
       ->where('status', self::STATUS_INACTIVE);
   }
 
-  static function withoutSegments($orm) {
+  public static function withoutSegments($orm) {
     return $orm->select(MP_SUBSCRIBERS_TABLE . '.*')
       ->whereRaw(
         MP_SUBSCRIBERS_TABLE . '.id NOT IN (
@@ -701,7 +701,7 @@ class Subscriber extends Model {
       );
   }
 
-  static function createMultiple($columns, $values) {
+  public static function createMultiple($columns, $values) {
     return self::rawExecute(
       'INSERT INTO `' . self::$_table . '` ' .
       '(' . implode(', ', $columns) . ') ' .
@@ -716,7 +716,7 @@ class Subscriber extends Model {
     );
   }
 
-  static function updateMultiple($columns, $subscribers, $updated_at = false) {
+  public static function updateMultiple($columns, $subscribers, $updated_at = false) {
     $ignore_columns_on_update = [
       'wp_user_id',
       'is_woocommerce_user',
@@ -773,13 +773,13 @@ class Subscriber extends Model {
     );
   }
 
-  static function findSubscribersInSegments(array $subscribers_ids, array $segments_ids) {
+  public static function findSubscribersInSegments(array $subscribers_ids, array $segments_ids) {
     return self::getSubscribedInSegments($segments_ids)
       ->whereIn('subscribers.id', $subscribers_ids)
       ->select('subscribers.*');
   }
 
-  static function extractSubscribersIds(array $subscribers) {
+  public static function extractSubscribersIds(array $subscribers) {
     return array_filter(
       array_map(function($subscriber) {
         return (!empty($subscriber->id)) ? $subscriber->id : false;
@@ -787,7 +787,7 @@ class Subscriber extends Model {
     );
   }
 
-  static function setRequiredFieldsDefaultValues($data) {
+  public static function setRequiredFieldsDefaultValues($data) {
     $settings = SettingsController::getInstance();
     $required_field_default_values = [
       'first_name' => '',
@@ -804,7 +804,7 @@ class Subscriber extends Model {
     return $data;
   }
 
-  static function extractCustomFieldsFromFromObject($data) {
+  public static function extractCustomFieldsFromFromObject($data) {
     $custom_fields = [];
     foreach ($data as $key => $value) {
       if (strpos($key, 'cf_') === 0) {
@@ -836,7 +836,7 @@ class Subscriber extends Model {
    * @see https://kb.mailpoet.com/article/195-add-subscribers-through-your-own-form-or-plugin
    * @deprecated
    */
-  static function subscribe($subscriber_data = [], $segment_ids = []) {
+  public static function subscribe($subscriber_data = [], $segment_ids = []) {
     trigger_error('Calling Subscriber::subscribe() is deprecated and will be removed. Use MailPoet\API\MP\v1\API instead. ', E_USER_DEPRECATED);
     $service = ContainerWrapper::getInstance()->get(\MailPoet\Subscribers\SubscriberActions::class);
     return $service->subscribe($subscriber_data, $segment_ids);
diff --git a/lib/Models/SubscriberCustomField.php b/lib/Models/SubscriberCustomField.php
index 7c3ab68f6c..c6d28eab3d 100644
--- a/lib/Models/SubscriberCustomField.php
+++ b/lib/Models/SubscriberCustomField.php
@@ -14,7 +14,7 @@ use function MailPoetVendor\array_column;
 class SubscriberCustomField extends Model {
   public static $_table = MP_SUBSCRIBER_CUSTOM_FIELD_TABLE;
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     $custom_field = CustomField::findOne($data['custom_field_id']);
     if ($custom_field instanceof CustomField) {
       $custom_field = $custom_field->asArray();
@@ -49,7 +49,7 @@ class SubscriberCustomField extends Model {
     ]);
   }
 
-  static function createMultiple($values) {
+  public static function createMultiple($values) {
     return self::rawExecute(
       'INSERT IGNORE INTO `' . self::$_table . '` ' .
       '(custom_field_id, subscriber_id, value) ' .
@@ -63,7 +63,7 @@ class SubscriberCustomField extends Model {
     );
   }
 
-  static function updateMultiple($values) {
+  public static function updateMultiple($values) {
     $subscriber_ids = array_unique(array_column($values, 1));
     $query = sprintf(
       "UPDATE `%s` SET value = (CASE %s ELSE value END) WHERE subscriber_id IN (%s)",
@@ -77,13 +77,13 @@ class SubscriberCustomField extends Model {
     );
   }
 
-  static function deleteSubscriberRelations($subscriber) {
+  public static function deleteSubscriberRelations($subscriber) {
     if ($subscriber === false) return false;
     $relations = self::where('subscriber_id', $subscriber->id);
     return $relations->deleteMany();
   }
 
-  static function deleteManySubscriberRelations(array $subscriber_ids) {
+  public static function deleteManySubscriberRelations(array $subscriber_ids) {
     if (empty($subscriber_ids)) return false;
     $relations = self::whereIn('subscriber_id', $subscriber_ids);
     return $relations->deleteMany();
diff --git a/lib/Models/SubscriberSegment.php b/lib/Models/SubscriberSegment.php
index c2cb643b80..6576df75c0 100644
--- a/lib/Models/SubscriberSegment.php
+++ b/lib/Models/SubscriberSegment.php
@@ -12,11 +12,11 @@ namespace MailPoet\Models;
 class SubscriberSegment extends Model {
   public static $_table = MP_SUBSCRIBER_SEGMENT_TABLE;
 
-  function subscriber() {
+  public function subscriber() {
     return $this->has_one(__NAMESPACE__ . '\Subscriber', 'id', 'subscriber_id');
   }
 
-  static function unsubscribeFromSegments($subscriber, $segment_ids = []) {
+  public static function unsubscribeFromSegments($subscriber, $segment_ids = []) {
     if ($subscriber === false) return false;
 
     // Reset confirmation emails count, so user can resubscribe
@@ -59,7 +59,7 @@ class SubscriberSegment extends Model {
     return true;
   }
 
-  static function resubscribeToAllSegments($subscriber) {
+  public static function resubscribeToAllSegments($subscriber) {
     if ($subscriber === false) return false;
     // (re)subscribe to all segments linked to the subscriber
     return self::where('subscriber_id', $subscriber->id)
@@ -68,7 +68,7 @@ class SubscriberSegment extends Model {
       ->save();
   }
 
-  static function subscribeToSegments($subscriber, $segment_ids = []) {
+  public static function subscribeToSegments($subscriber, $segment_ids = []) {
     if ($subscriber === false) return false;
     if (!empty($segment_ids)) {
       // subscribe to specified segments
@@ -85,12 +85,12 @@ class SubscriberSegment extends Model {
     }
   }
 
-  static function resetSubscriptions($subscriber, $segment_ids = []) {
+  public static function resetSubscriptions($subscriber, $segment_ids = []) {
     self::unsubscribeFromSegments($subscriber);
     return self::subscribeToSegments($subscriber, $segment_ids);
   }
 
-  static function subscribeManyToSegments(
+  public static function subscribeManyToSegments(
     $subscriber_ids = [],
     $segment_ids = []
   ) {
@@ -119,7 +119,7 @@ class SubscriberSegment extends Model {
     return true;
   }
 
-  static function deleteManySubscriptions($subscriber_ids = [], $segment_ids = []) {
+  public static function deleteManySubscriptions($subscriber_ids = [], $segment_ids = []) {
     if (empty($subscriber_ids)) return false;
 
     // delete subscribers' relations to segments (except WP and WooCommerce segments)
@@ -147,7 +147,7 @@ class SubscriberSegment extends Model {
     return $subscriptions->deleteMany();
   }
 
-  static function deleteSubscriptions($subscriber, $segment_ids = []) {
+  public static function deleteSubscriptions($subscriber, $segment_ids = []) {
     if ($subscriber === false) return false;
 
     $wp_segment = Segment::getWPSegment();
@@ -162,11 +162,11 @@ class SubscriberSegment extends Model {
     return $subscriptions->deleteMany();
   }
 
-  static function subscribed($orm) {
+  public static function subscribed($orm) {
     return $orm->where('status', Subscriber::STATUS_SUBSCRIBED);
   }
 
-  static function createOrUpdate($data = []) {
+  public static function createOrUpdate($data = []) {
     $keys = false;
     if (isset($data['subscriber_id']) && isset($data['segment_id'])) {
       $keys = [
diff --git a/lib/Models/SubscribersInDynamicSegment.php b/lib/Models/SubscribersInDynamicSegment.php
index df8a3b1c3d..2d4f9c7586 100644
--- a/lib/Models/SubscribersInDynamicSegment.php
+++ b/lib/Models/SubscribersInDynamicSegment.php
@@ -9,7 +9,7 @@ use MailPoet\WooCommerce\Helper as WooCommerceHelper;
 
 class SubscribersInDynamicSegment extends Subscriber {
 
-  static function listingQuery(array $data = []) {
+  public static function listingQuery(array $data = []) {
     $query = self::select(self::$_table . '.*');
     $single_segment_loader = new SingleSegmentLoader(new DBMapper());
     $dynamic_segment = $single_segment_loader->load($data['filter']['segment']);
diff --git a/lib/Newsletter/AutomatedLatestContent.php b/lib/Newsletter/AutomatedLatestContent.php
index d3d2468f5b..6721be8163 100644
--- a/lib/Newsletter/AutomatedLatestContent.php
+++ b/lib/Newsletter/AutomatedLatestContent.php
@@ -15,13 +15,13 @@ class AutomatedLatestContent {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function __construct($newsletter_id = false, $newer_than_timestamp = false) {
+  public function __construct($newsletter_id = false, $newer_than_timestamp = false) {
     $this->newsletter_id = $newsletter_id;
     $this->newer_than_timestamp = $newer_than_timestamp;
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function filterOutSentPosts($where) {
+  public function filterOutSentPosts($where) {
     $sentPostsQuery = 'SELECT ' . MP_NEWSLETTER_POSTS_TABLE . '.post_id FROM '
       . MP_NEWSLETTER_POSTS_TABLE . ' WHERE '
       . MP_NEWSLETTER_POSTS_TABLE . ".newsletter_id='" . $this->newsletter_id . "'";
@@ -41,7 +41,7 @@ class AutomatedLatestContent {
     $query->is_home = false;
   }
 
-  function getPosts($args, $posts_to_exclude = []) {
+  public function getPosts($args, $posts_to_exclude = []) {
     // Get posts as logged out user, so private posts hidden by other plugins (e.g. UAM) are also excluded
     $current_user_id = WPFunctions::get()->getCurrentUserId();
     WPFunctions::get()->wpSetCurrentUser(0);
@@ -108,12 +108,12 @@ class AutomatedLatestContent {
     return $posts;
   }
 
-  function transformPosts($args, $posts) {
+  public function transformPosts($args, $posts) {
     $transformer = new Transformer($args);
     return $transformer->transform($posts);
   }
 
-  function constructTaxonomiesQuery($args) {
+  public function constructTaxonomiesQuery($args) {
     $taxonomies_query = [];
     if (isset($args['terms']) && is_array($args['terms'])) {
       $taxonomies = [];
diff --git a/lib/Newsletter/Editor/LayoutHelper.php b/lib/Newsletter/Editor/LayoutHelper.php
index 3f25e4cdd2..56b4f0d39f 100644
--- a/lib/Newsletter/Editor/LayoutHelper.php
+++ b/lib/Newsletter/Editor/LayoutHelper.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Newsletter\Editor;
 
 class LayoutHelper {
-  static function row($blocks, $styles = []) {
+  public static function row($blocks, $styles = []) {
     if (empty($styles['backgroundColor'])) {
       $styles['backgroundColor'] = 'transparent';
     }
@@ -15,7 +15,7 @@ class LayoutHelper {
     ];
   }
 
-  static function col($blocks, $styles = []) {
+  public static function col($blocks, $styles = []) {
     if (empty($styles['backgroundColor'])) {
       $styles['backgroundColor'] = 'transparent';
     }
diff --git a/lib/Newsletter/Editor/MetaInformationManager.php b/lib/Newsletter/Editor/MetaInformationManager.php
index 689da92721..8160251553 100644
--- a/lib/Newsletter/Editor/MetaInformationManager.php
+++ b/lib/Newsletter/Editor/MetaInformationManager.php
@@ -6,7 +6,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class MetaInformationManager {
 
-  function appendMetaInformation($content, $post, $args) {
+  public function appendMetaInformation($content, $post, $args) {
     // Append author and categories above and below contents
     foreach (['above', 'below'] as $position) {
       $position_field = $position . 'Text';
diff --git a/lib/Newsletter/Editor/PostContentManager.php b/lib/Newsletter/Editor/PostContentManager.php
index f24d4dd9f2..ddcf0d3929 100644
--- a/lib/Newsletter/Editor/PostContentManager.php
+++ b/lib/Newsletter/Editor/PostContentManager.php
@@ -13,13 +13,13 @@ class PostContentManager {
   /** @var WooCommerceHelper */
   private $woocommerce_helper;
 
-  function __construct(WooCommerceHelper $woocommerce_helper = null) {
+  public function __construct(WooCommerceHelper $woocommerce_helper = null) {
     $wp = new WPFunctions;
     $this->max_excerpt_length = $wp->applyFilters('mailpoet_newsletter_post_excerpt_length', $this->max_excerpt_length);
     $this->woocommerce_helper = $woocommerce_helper ?: new WooCommerceHelper();
   }
 
-  function getContent($post, $displayType) {
+  public function getContent($post, $displayType) {
     if ($displayType === 'titleOnly') {
       return '';
     }
@@ -38,7 +38,7 @@ class PostContentManager {
     return self::stripShortCodes($post->post_content);
   }
 
-  function filterContent($content, $display_type, $with_post_class = true) {
+  public function filterContent($content, $display_type, $with_post_class = true) {
     $content = self::convertEmbeddedContent($content);
 
     // convert h4 h5 h6 to h3
diff --git a/lib/Newsletter/Editor/PostListTransformer.php b/lib/Newsletter/Editor/PostListTransformer.php
index 326ba49cbb..454af5ee77 100644
--- a/lib/Newsletter/Editor/PostListTransformer.php
+++ b/lib/Newsletter/Editor/PostListTransformer.php
@@ -7,12 +7,12 @@ class PostListTransformer {
   private $args;
   private $transformer;
 
-  function __construct($args) {
+  public function __construct($args) {
     $this->args = $args;
     $this->transformer = new PostTransformer($args);
   }
 
-  function transform($posts) {
+  public function transform($posts) {
     $results = [];
     $use_divider = filter_var($this->args['showDivider'], FILTER_VALIDATE_BOOLEAN);
 
diff --git a/lib/Newsletter/Editor/PostTransformer.php b/lib/Newsletter/Editor/PostTransformer.php
index 5e00630c4a..ab4478e942 100644
--- a/lib/Newsletter/Editor/PostTransformer.php
+++ b/lib/Newsletter/Editor/PostTransformer.php
@@ -13,7 +13,7 @@ class PostTransformer {
   /** @var string */
   private $image_position;
 
-  function __construct($args, PostTransformerContentsExtractor $extractor = null) {
+  public function __construct($args, PostTransformerContentsExtractor $extractor = null) {
     $this->args = $args;
     $this->with_layout = isset($args['withLayout']) ? (bool)filter_var($args['withLayout'], FILTER_VALIDATE_BOOLEAN) : false;
     $this->image_position = 'left';
@@ -23,7 +23,7 @@ class PostTransformer {
     $this->extractor = $extractor;
   }
 
-  function getDivider() {
+  public function getDivider() {
     if (empty($this->with_layout)) {
       return $this->args['divider'];
     }
@@ -32,7 +32,7 @@ class PostTransformer {
     ]);
   }
 
-  function transform($post) {
+  public function transform($post) {
     if (empty($this->with_layout)) {
       return $this->getStructure($post);
     }
diff --git a/lib/Newsletter/Editor/PostTransformerContentsExtractor.php b/lib/Newsletter/Editor/PostTransformerContentsExtractor.php
index f50f558bc1..e3da7168a8 100644
--- a/lib/Newsletter/Editor/PostTransformerContentsExtractor.php
+++ b/lib/Newsletter/Editor/PostTransformerContentsExtractor.php
@@ -16,13 +16,13 @@ class PostTransformerContentsExtractor {
   /** @var WooCommerceHelper */
   private $woocommerce_helper;
 
-  function __construct($args) {
+  public function __construct($args) {
     $this->args = $args;
     $this->wp = new WPFunctions();
     $this->woocommerce_helper = new WooCommerceHelper();
   }
 
-  function getContent($post, $with_post_class, $display_type) {
+  public function getContent($post, $with_post_class, $display_type) {
     $content_manager = new PostContentManager();
     $meta_manager = new MetaInformationManager();
 
@@ -66,7 +66,7 @@ class PostTransformerContentsExtractor {
     return $image_info;
   }
 
-  function getFeaturedImage($post) {
+  public function getFeaturedImage($post) {
     $post_id = $post->ID;
     $post_title = $this->sanitizeTitle($post->post_title);
     $image_full_width = (bool)filter_var($this->args['imageFullWidth'], FILTER_VALIDATE_BOOLEAN);
@@ -124,7 +124,7 @@ class PostTransformerContentsExtractor {
     ];
   }
 
-  function getTitle($post) {
+  public function getTitle($post) {
     $title = $this->sanitizeTitle($post->post_title);
 
     if (filter_var($this->args['titleIsLink'], FILTER_VALIDATE_BOOLEAN)) {
@@ -181,7 +181,7 @@ class PostTransformerContentsExtractor {
     return $content;
   }
 
-  function isProduct($post) {
+  public function isProduct($post) {
     return $post->post_type === 'product';
   }
 
diff --git a/lib/Newsletter/Editor/StructureTransformer.php b/lib/Newsletter/Editor/StructureTransformer.php
index b0443ebe66..15189c1600 100644
--- a/lib/Newsletter/Editor/StructureTransformer.php
+++ b/lib/Newsletter/Editor/StructureTransformer.php
@@ -8,7 +8,7 @@ use pQuery\DomNode;
 
 class StructureTransformer {
 
-  function transform($content, $image_full_width) {
+  public function transform($content, $image_full_width) {
     $root = pQuery::parseStr($content);
 
     $this->hoistImagesToRoot($root);
diff --git a/lib/Newsletter/Editor/TitleListTransformer.php b/lib/Newsletter/Editor/TitleListTransformer.php
index 2e8ebe3139..30c0ddb155 100644
--- a/lib/Newsletter/Editor/TitleListTransformer.php
+++ b/lib/Newsletter/Editor/TitleListTransformer.php
@@ -8,11 +8,11 @@ class TitleListTransformer {
 
   private $args;
 
-  function __construct($args) {
+  public function __construct($args) {
     $this->args = $args;
   }
 
-  function transform($posts) {
+  public function transform($posts) {
     $results = array_map(function($post) {
       return $this->getPostTitle($post);
     }, $posts);
diff --git a/lib/Newsletter/Editor/Transformer.php b/lib/Newsletter/Editor/Transformer.php
index e501e7dbdc..492423480b 100644
--- a/lib/Newsletter/Editor/Transformer.php
+++ b/lib/Newsletter/Editor/Transformer.php
@@ -6,7 +6,7 @@ class Transformer {
 
   private $transformer;
 
-  function __construct($args) {
+  public function __construct($args) {
     $title_list_only = $args['displayType'] === 'titleOnly' && $args['titleFormat'] === 'ul';
 
     if ($title_list_only) $transformer = new TitleListTransformer($args);
@@ -14,7 +14,7 @@ class Transformer {
     $this->transformer = $transformer;
   }
 
-  function transform($posts) {
+  public function transform($posts) {
     return $this->transformer->transform($posts);
   }
 }
diff --git a/lib/Newsletter/Links/Links.php b/lib/Newsletter/Links/Links.php
index 72f248e52c..bd326a9b85 100644
--- a/lib/Newsletter/Links/Links.php
+++ b/lib/Newsletter/Links/Links.php
@@ -21,14 +21,14 @@ class Links {
   const LINK_TYPE_SHORTCODE = 'shortcode';
   const LINK_TYPE_URL = 'link';
 
-  static function process($content, $newsletter_id, $queue_id) {
+  public static function process($content, $newsletter_id, $queue_id) {
     $extracted_links = self::extract($content);
     $saved_links = self::load($newsletter_id, $queue_id);
     $processed_links = self::hash($extracted_links, $saved_links);
     return self::replace($content, $processed_links);
   }
 
-  static function extract($content) {
+  public static function extract($content) {
     $extracted_links = [];
     // extract link shortcodes
     $shortcodes = new Shortcodes();
@@ -56,7 +56,7 @@ class Links {
     return array_unique($extracted_links, SORT_REGULAR);
   }
 
-  static function replace($content, $processed_links) {
+  public static function replace($content, $processed_links) {
     // replace HTML anchor tags
     $DOM = DomParser::parseStr($content);
     foreach ($DOM->query('a') as $link) {
@@ -87,7 +87,7 @@ class Links {
     ];
   }
 
-  static function replaceSubscriberData(
+  public static function replaceSubscriberData(
     $subscriber_id,
     $queue_id,
     $content,
@@ -122,7 +122,7 @@ class Links {
     return $content;
   }
 
-  static function save(array $links, $newsletter_id, $queue_id) {
+  public static function save(array $links, $newsletter_id, $queue_id) {
     foreach ($links as $link) {
       if (isset($link['id']))
         continue;
@@ -136,7 +136,7 @@ class Links {
     }
   }
 
-  static function ensureUnsubscribeLink(array $processed_links) {
+  public static function ensureUnsubscribeLink(array $processed_links) {
     if (in_array(
       NewsletterLink::UNSUBSCRIBE_LINK_SHORT_CODE,
       array_column($processed_links, 'link'))
@@ -150,7 +150,7 @@ class Links {
     return $processed_links;
   }
 
-  static function convertHashedLinksToShortcodesAndUrls($content, $queue_id, $convert_all = false) {
+  public static function convertHashedLinksToShortcodesAndUrls($content, $queue_id, $convert_all = false) {
     preg_match_all(self::getLinkRegex(), $content, $links);
     $links = array_unique(Helpers::flattenArray($links));
     foreach ($links as $link) {
@@ -170,7 +170,7 @@ class Links {
     return $content;
   }
 
-  static function getLinkRegex() {
+  public static function getLinkRegex() {
     return sprintf(
       '/((%s|%s)(?:-\w+)?)/',
       preg_quote(self::DATA_TAG_CLICK),
@@ -178,7 +178,7 @@ class Links {
     );
   }
 
-  static function createUrlDataObject(
+  public static function createUrlDataObject(
     $subscriber_id, $subscriber_link_token, $queue_id, $link_hash, $preview
   ) {
     return [
@@ -190,7 +190,7 @@ class Links {
     ];
   }
 
-  static function transformUrlDataObject($data) {
+  public static function transformUrlDataObject($data) {
     reset($data);
     if (!is_int(key($data))) return $data;
     $transformed_data = [];
diff --git a/lib/Newsletter/Renderer/Blocks/Button.php b/lib/Newsletter/Renderer/Blocks/Button.php
index a9a5dc4a78..eb6a7bd71b 100644
--- a/lib/Newsletter/Renderer/Blocks/Button.php
+++ b/lib/Newsletter/Renderer/Blocks/Button.php
@@ -6,7 +6,7 @@ use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 use MailPoet\Newsletter\Renderer\StylesHelper;
 
 class Button {
-  static function render($element, $column_base_width) {
+  public static function render($element, $column_base_width) {
     $element['styles']['block']['width'] = self::calculateWidth($element, $column_base_width);
     $styles = 'display:inline-block;-webkit-text-size-adjust:none;mso-hide:all;text-decoration:none !important;text-align:center;' . StylesHelper::getBlockStyles($element, $exclude = ['textAlign']);
     $styles = EHelper::escapeHtmlStyleAttr($styles);
@@ -43,7 +43,7 @@ class Button {
     return $template;
   }
 
-  static function calculateWidth($element, $column_base_width) {
+  public static function calculateWidth($element, $column_base_width) {
     $column_width = $column_base_width - (StylesHelper::$padding_width * 2);
     $border_width = (int)$element['styles']['block']['borderWidth'];
     $button_width = (int)$element['styles']['block']['width'];
diff --git a/lib/Newsletter/Renderer/Blocks/Divider.php b/lib/Newsletter/Renderer/Blocks/Divider.php
index c5cb6c1e75..c370b4ce36 100644
--- a/lib/Newsletter/Renderer/Blocks/Divider.php
+++ b/lib/Newsletter/Renderer/Blocks/Divider.php
@@ -6,7 +6,7 @@ use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 use MailPoet\Newsletter\Renderer\StylesHelper;
 
 class Divider {
-  static function render($element) {
+  public static function render($element) {
     $background_color = $element['styles']['block']['backgroundColor'];
     $divider_cell_style = "border-top-width: {$element['styles']['block']['borderWidth']};";
     $divider_cell_style .= "border-top-style: {$element['styles']['block']['borderStyle']};";
diff --git a/lib/Newsletter/Renderer/Blocks/Footer.php b/lib/Newsletter/Renderer/Blocks/Footer.php
index b8b1947ac0..8d553dbcd7 100644
--- a/lib/Newsletter/Renderer/Blocks/Footer.php
+++ b/lib/Newsletter/Renderer/Blocks/Footer.php
@@ -8,7 +8,7 @@ use MailPoet\Util\pQuery\pQuery;
 use MailPoetVendor\CSS;
 
 class Footer {
-  static function render($element) {
+  public static function render($element) {
     $element['text'] = preg_replace('/\n/', '<br />', $element['text']);
     $element['text'] = preg_replace('/(<\/?p.*?>)/i', '', $element['text']);
     $line_height = sprintf(
diff --git a/lib/Newsletter/Renderer/Blocks/Header.php b/lib/Newsletter/Renderer/Blocks/Header.php
index bac44cbf16..f9e3442c7d 100644
--- a/lib/Newsletter/Renderer/Blocks/Header.php
+++ b/lib/Newsletter/Renderer/Blocks/Header.php
@@ -8,7 +8,7 @@ use MailPoet\Util\pQuery\pQuery;
 use MailPoetVendor\CSS;
 
 class Header {
-  static function render($element) {
+  public static function render($element) {
     $element['text'] = preg_replace('/\n/', '<br />', $element['text']);
     $element['text'] = preg_replace('/(<\/?p.*?>)/i', '', $element['text']);
     $line_height = sprintf(
diff --git a/lib/Newsletter/Renderer/Blocks/Image.php b/lib/Newsletter/Renderer/Blocks/Image.php
index eb6c008bb1..ec387d1bf9 100644
--- a/lib/Newsletter/Renderer/Blocks/Image.php
+++ b/lib/Newsletter/Renderer/Blocks/Image.php
@@ -7,7 +7,7 @@ use MailPoet\Newsletter\Renderer\StylesHelper;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Image {
-  static function render($element, $column_base_width) {
+  public static function render($element, $column_base_width) {
     if (empty($element['src'])) {
       return '';
     }
@@ -51,7 +51,7 @@ class Image {
     return $template;
   }
 
-  static function adjustImageDimensions($element, $column_base_width) {
+  public static function adjustImageDimensions($element, $column_base_width) {
     $padded_width = StylesHelper::$padding_width * 2;
     // scale image to fit column width
     if ($element['width'] > $column_base_width) {
diff --git a/lib/Newsletter/Renderer/Blocks/Renderer.php b/lib/Newsletter/Renderer/Blocks/Renderer.php
index 7a8984893c..0010a946bc 100644
--- a/lib/Newsletter/Renderer/Blocks/Renderer.php
+++ b/lib/Newsletter/Renderer/Blocks/Renderer.php
@@ -12,7 +12,7 @@ class Renderer {
   public $posts;
   public $ALC;
 
-  function __construct(array $newsletter) {
+  public function __construct(array $newsletter) {
     $this->newsletter = $newsletter;
     $this->posts = [];
     $newer_than_timestamp = false;
@@ -31,7 +31,7 @@ class Renderer {
     );
   }
 
-  function render($data) {
+  public function render($data) {
     $column_count = count($data['blocks']);
     $columns_layout = isset($data['columnLayout']) ? $data['columnLayout'] : null;
     $column_widths = ColumnsHelper::columnWidth($column_count, $columns_layout);
@@ -63,7 +63,7 @@ class Renderer {
     return $block_content;
   }
 
-  function createElementFromBlockType($block, $column_base_width) {
+  public function createElementFromBlockType($block, $column_base_width) {
     if ($block['type'] === 'automatedLatestContent') {
       $content = $this->processAutomatedLatestContent($block, $column_base_width);
       return $content;
@@ -76,7 +76,7 @@ class Renderer {
     return $block_class::render($block, $column_base_width);
   }
 
-  function automatedLatestContentTransformedPosts($args) {
+  public function automatedLatestContentTransformedPosts($args) {
     $posts_to_exclude = $this->getPosts();
     $ALC_posts = $this->ALC->getPosts($args, $posts_to_exclude);
     foreach ($ALC_posts as $post) {
@@ -86,7 +86,7 @@ class Renderer {
     return $this->ALC->transformPosts($args, $ALC_posts);
   }
 
-  function processAutomatedLatestContent($args, $column_base_width) {
+  public function processAutomatedLatestContent($args, $column_base_width) {
     $transformed_posts = [
       'blocks' => $this->automatedLatestContentTransformedPosts($args),
     ];
@@ -95,11 +95,11 @@ class Renderer {
     return $rendered_posts;
   }
 
-  function getPosts() {
+  public function getPosts() {
     return $this->posts;
   }
 
-  function setPosts($posts) {
+  public function setPosts($posts) {
     return $this->posts = $posts;
   }
 }
diff --git a/lib/Newsletter/Renderer/Blocks/Social.php b/lib/Newsletter/Renderer/Blocks/Social.php
index 9951ef5730..a193754b9b 100644
--- a/lib/Newsletter/Renderer/Blocks/Social.php
+++ b/lib/Newsletter/Renderer/Blocks/Social.php
@@ -5,7 +5,7 @@ namespace MailPoet\Newsletter\Renderer\Blocks;
 use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 
 class Social {
-  static function render($element) {
+  public static function render($element) {
     $icons_block = '';
     if (is_array($element['icons'])) {
       foreach ($element['icons'] as $index => $icon) {
@@ -15,10 +15,10 @@ class Social {
 
         $style = 'width:' . $icon['width'] . ';height:' . $icon['width'] . ';-ms-interpolation-mode:bicubic;border:0;display:inline;outline:none;';
         $icons_block .= '<a href="' . EHelper::escapeHtmlLinkAttr($icon['link']) . '" style="text-decoration:none!important;"
-        ><img 
+        ><img
           src="' . EHelper::escapeHtmlLinkAttr($icon['image']) . '"
-          width="' . (int)$icon['width'] . '" 
-          height="' . (int)$icon['height'] . '" 
+          width="' . (int)$icon['width'] . '"
+          height="' . (int)$icon['height'] . '"
           style="' . EHelper::escapeHtmlStyleAttr($style) . '"
           alt="' . EHelper::escapeHtmlAttr($icon['iconType']) . '"
         ></a>&nbsp;';
diff --git a/lib/Newsletter/Renderer/Blocks/Spacer.php b/lib/Newsletter/Renderer/Blocks/Spacer.php
index 61d9101502..409928e45f 100644
--- a/lib/Newsletter/Renderer/Blocks/Spacer.php
+++ b/lib/Newsletter/Renderer/Blocks/Spacer.php
@@ -5,7 +5,7 @@ namespace MailPoet\Newsletter\Renderer\Blocks;
 use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 
 class Spacer {
-  static function render($element) {
+  public static function render($element) {
     $height = (int)$element['styles']['block']['height'];
     $background_color = EHelper::escapeHtmlAttr($element['styles']['block']['backgroundColor']);
     $template = '
diff --git a/lib/Newsletter/Renderer/Blocks/Text.php b/lib/Newsletter/Renderer/Blocks/Text.php
index 51094e214a..e944f61d47 100644
--- a/lib/Newsletter/Renderer/Blocks/Text.php
+++ b/lib/Newsletter/Renderer/Blocks/Text.php
@@ -8,7 +8,7 @@ use MailPoet\Newsletter\Renderer\StylesHelper;
 use MailPoet\Util\pQuery\pQuery;
 
 class Text {
-  static function render($element) {
+  public static function render($element) {
     $html = $element['text'];
     // replace &nbsp; with spaces
     $html = str_replace('&nbsp;', ' ', $html);
@@ -27,7 +27,7 @@ class Text {
     return $template;
   }
 
-  static function convertBlockquotesToTables($html) {
+  public static function convertBlockquotesToTables($html) {
     $DOM_parser = new pQuery();
     $DOM = $DOM_parser->parseStr($html);
     $blockquotes = $DOM->query('blockquote');
@@ -72,7 +72,7 @@ class Text {
     return $DOM->__toString();
   }
 
-  static function convertParagraphsToTables($html) {
+  public static function convertParagraphsToTables($html) {
     $DOM_parser = new pQuery();
     $DOM = $DOM_parser->parseStr($html);
     $paragraphs = $DOM->query('p');
@@ -136,7 +136,7 @@ class Text {
     return $DOM->__toString();
   }
 
-  static function styleLists($html) {
+  public static function styleLists($html) {
     $DOM_parser = new pQuery();
     $DOM = $DOM_parser->parseStr($html);
     $lists = $DOM->query('ol, ul, li');
@@ -156,7 +156,7 @@ class Text {
     return $DOM->__toString();
   }
 
-  static function styleHeadings($html) {
+  public static function styleHeadings($html) {
     $DOM_parser = new pQuery();
     $DOM = $DOM_parser->parseStr($html);
     $headings = $DOM->query('h1, h2, h3, h4');
@@ -169,11 +169,11 @@ class Text {
     return $DOM->__toString();
   }
 
-  static function removeLastLineBreak($html) {
+  public static function removeLastLineBreak($html) {
     return preg_replace('/(^)?(<br[^>]*?\/?>)+$/i', '', $html);
   }
 
-  static function insertLineBreak($element) {
+  public static function insertLineBreak($element) {
     $element->parent->insertChild(
       [
         'tag_name' => 'br',
diff --git a/lib/Newsletter/Renderer/Columns/ColumnsHelper.php b/lib/Newsletter/Renderer/Columns/ColumnsHelper.php
index 50a6741749..cc89b730cb 100644
--- a/lib/Newsletter/Renderer/Columns/ColumnsHelper.php
+++ b/lib/Newsletter/Renderer/Columns/ColumnsHelper.php
@@ -24,22 +24,22 @@ class ColumnsHelper {
   ];
 
   /** @return int[] */
-  static function columnWidth($columns_count, $columns_layout) {
+  public static function columnWidth($columns_count, $columns_layout) {
     if (isset(self::$columns_width[$columns_layout])) {
       return self::$columns_width[$columns_layout];
     }
     return self::$columns_width[$columns_count];
   }
 
-  static function columnClass($columns_count) {
+  public static function columnClass($columns_count) {
     return self::$columns_class[$columns_count];
   }
 
-  static function columnClasses() {
+  public static function columnClasses() {
     return self::$columns_class;
   }
 
-  static function columnAlignment($columns_count) {
+  public static function columnAlignment($columns_count) {
     return self::$columns_alignment[$columns_count];
   }
 }
diff --git a/lib/Newsletter/Renderer/Columns/Renderer.php b/lib/Newsletter/Renderer/Columns/Renderer.php
index 4f77361dbe..1147309e2c 100644
--- a/lib/Newsletter/Renderer/Columns/Renderer.php
+++ b/lib/Newsletter/Renderer/Columns/Renderer.php
@@ -6,7 +6,7 @@ use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 
 class Renderer {
 
-  function render($content_block, $columns_data) {
+  public function render($content_block, $columns_data) {
 
     $columns_count = count($content_block['blocks']);
 
@@ -24,7 +24,7 @@ class Renderer {
     return $template['content_start'] . $content . $template['content_end'];
   }
 
-  function getOneColumnTemplate($styles, $image) {
+  public function getOneColumnTemplate($styles, $image) {
     $background_css = $this->getBackgroundCss($styles, $image);
     $template['content_start'] = '
       <tr>
@@ -99,7 +99,7 @@ class Renderer {
       </td>';
   }
 
-  function getMultipleColumnsContentStart($width, $alignment, $class) {
+  public function getMultipleColumnsContentStart($width, $alignment, $class) {
     return '
       <td width="' . $width . '" valign="top">
         <![endif]--><div style="display:inline-block; max-width:' . $width . 'px; vertical-align:top; width:100%;">
diff --git a/lib/Newsletter/Renderer/EscapeHelper.php b/lib/Newsletter/Renderer/EscapeHelper.php
index e0e35807b8..868b5ce3d3 100644
--- a/lib/Newsletter/Renderer/EscapeHelper.php
+++ b/lib/Newsletter/Renderer/EscapeHelper.php
@@ -7,7 +7,7 @@ class EscapeHelper {
    * @param string $string
    * @return string
    */
-  static function escapeHtmlText($string) {
+  public static function escapeHtmlText($string) {
     return htmlspecialchars((string)$string, ENT_NOQUOTES, 'UTF-8');
   }
 
@@ -15,7 +15,7 @@ class EscapeHelper {
    * @param string $string
    * @return string
    */
-  static function escapeHtmlAttr($string) {
+  public static function escapeHtmlAttr($string) {
     return htmlspecialchars((string)$string, ENT_QUOTES, 'UTF-8');
   }
 
@@ -25,7 +25,7 @@ class EscapeHelper {
    * @param string $string
    * @return string
    */
-  static function escapeHtmlStyleAttr($string) {
+  public static function escapeHtmlStyleAttr($string) {
     return htmlspecialchars((string)$string, ENT_COMPAT, 'UTF-8');
   }
 
@@ -33,7 +33,7 @@ class EscapeHelper {
    * @param string $string
    * @return string
    */
-  static function unescapeHtmlStyleAttr($string) {
+  public static function unescapeHtmlStyleAttr($string) {
     return htmlspecialchars_decode((string)$string, ENT_COMPAT);
   }
 
@@ -41,7 +41,7 @@ class EscapeHelper {
    * @param string $string
    * @return string
    */
-  static function escapeHtmlLinkAttr($string) {
+  public static function escapeHtmlLinkAttr($string) {
     $string = self::escapeHtmlAttr($string);
     if (preg_match('/\s*(javascript:|data:text|data:application)/ui', $string) === 1) {
       return '';
diff --git a/lib/Newsletter/Renderer/PostProcess/OpenTracking.php b/lib/Newsletter/Renderer/PostProcess/OpenTracking.php
index 7acd52b187..79dcbfbacc 100644
--- a/lib/Newsletter/Renderer/PostProcess/OpenTracking.php
+++ b/lib/Newsletter/Renderer/PostProcess/OpenTracking.php
@@ -8,7 +8,7 @@ use MailPoet\Util\pQuery\pQuery;
 use MailPoet\WP\Functions as WPFunctions;
 
 class OpenTracking {
-  static function process($template) {
+  public static function process($template) {
     $DOM = new pQuery();
     $DOM = $DOM->parseStr($template);
     $template = $DOM->query('body');
@@ -23,7 +23,7 @@ class OpenTracking {
     return $DOM->__toString();
   }
 
-  static function addTrackingImage() {
+  public static function addTrackingImage() {
     WPFunctions::get()->addFilter(Renderer::FILTER_POST_PROCESS, function ($template) {
       return OpenTracking::process($template);
     });
diff --git a/lib/Newsletter/Renderer/Renderer.php b/lib/Newsletter/Renderer/Renderer.php
index eb9a7625e7..b90fa288cf 100644
--- a/lib/Newsletter/Renderer/Renderer.php
+++ b/lib/Newsletter/Renderer/Renderer.php
@@ -28,7 +28,7 @@ class Renderer {
   /**
    * @param \MailPoet\Models\Newsletter|array $newsletter
    */
-  function __construct($newsletter, $preview = false) {
+  public function __construct($newsletter, $preview = false) {
     $this->newsletter = ($newsletter instanceof Newsletter) ? $newsletter->asArray() : $newsletter;
     $this->preview = $preview;
     $this->blocks_renderer = new Blocks\Renderer($this->newsletter);
@@ -44,7 +44,7 @@ class Renderer {
     $this->mss_activated = $bridge->isMPSendingServiceEnabled();
   }
 
-  function render($type = false) {
+  public function render($type = false) {
     $newsletter = $this->newsletter;
     $body = (is_array($newsletter['body']))
       ? $newsletter['body']
diff --git a/lib/Newsletter/Renderer/StylesHelper.php b/lib/Newsletter/Renderer/StylesHelper.php
index 89645e44eb..677b361d41 100644
--- a/lib/Newsletter/Renderer/StylesHelper.php
+++ b/lib/Newsletter/Renderer/StylesHelper.php
@@ -62,14 +62,14 @@ class StylesHelper {
   static $heading_margin_multiplier = 0.3;
   static $padding_width = 20;
 
-  static function getBlockStyles($element, $ignore_specific_styles = false) {
+  public static function getBlockStyles($element, $ignore_specific_styles = false) {
     if (!isset($element['styles']['block'])) {
       return;
     }
     return self::getStyles($element['styles'], 'block', $ignore_specific_styles);
   }
 
-  static function getStyles($data, $type, $ignore_specific_styles = false) {
+  public static function getStyles($data, $type, $ignore_specific_styles = false) {
     $styles = array_map(function($attribute, $style) use ($ignore_specific_styles) {
       if (!$ignore_specific_styles || !in_array($attribute, $ignore_specific_styles)) {
         $style = StylesHelper::applyFontFamily($attribute, $style);
@@ -79,13 +79,13 @@ class StylesHelper {
     return implode('', $styles);
   }
 
-  static function translateCSSAttribute($attribute) {
+  public static function translateCSSAttribute($attribute) {
     return (array_key_exists($attribute, self::$css_attributes)) ?
       self::$css_attributes[$attribute] :
       $attribute;
   }
 
-  static function setStyle($style, $selector) {
+  public static function setStyle($style, $selector) {
     $css = $selector . '{' . PHP_EOL;
     $style = self::applyHeadingMargin($style, $selector);
     $style = self::applyLineHeight($style, $selector);
@@ -97,7 +97,7 @@ class StylesHelper {
     return $css;
   }
 
-  static function applyTextAlignment($block) {
+  public static function applyTextAlignment($block) {
     if (is_array($block)) {
       $text_alignment = isset($block['styles']['block']['textAlign']) ?
         strtolower($block['styles']['block']['textAlign']) :
@@ -113,21 +113,21 @@ class StylesHelper {
       $block . 'text-align:left;';
   }
 
-  static function applyFontFamily($attribute, $style) {
+  public static function applyFontFamily($attribute, $style) {
     if ($attribute !== 'fontFamily') return $style;
     return (isset(self::$font[$style])) ?
         self::$font[$style] :
         self::$font['Arial'];
   }
 
-  static function applyHeadingMargin($style, $selector) {
+  public static function applyHeadingMargin($style, $selector) {
     if (!preg_match('/h[1-4]/i', $selector)) return $style;
     $font_size = (int)$style['fontSize'];
     $style['margin'] = sprintf('0 0 %spx 0', self::$heading_margin_multiplier * $font_size);
     return $style;
   }
 
-  static function applyLineHeight($style, $selector) {
+  public static function applyLineHeight($style, $selector) {
     if (!preg_match('/mailpoet_paragraph|h[1-4]/i', $selector)) return $style;
     $line_height = isset($style['lineHeight']) ? (float)$style['lineHeight'] : self::$default_line_height;
     $font_size = (int)$style['fontSize'];
@@ -145,7 +145,7 @@ class StylesHelper {
     return array_keys($font_names);
   }
 
-  static function getCustomFontsLinks($styles) {
+  public static function getCustomFontsLinks($styles) {
     $links = [];
     foreach (self::getCustomFontsNames($styles) as $name) {
       $links[] = urlencode($name) . ':400,400i,700,700i';
diff --git a/lib/Newsletter/Scheduler/AutomaticEmailScheduler.php b/lib/Newsletter/Scheduler/AutomaticEmailScheduler.php
index 654aff70db..77df200c46 100644
--- a/lib/Newsletter/Scheduler/AutomaticEmailScheduler.php
+++ b/lib/Newsletter/Scheduler/AutomaticEmailScheduler.php
@@ -10,7 +10,7 @@ use MailPoet\Tasks\Sending as SendingTask;
 
 class AutomaticEmailScheduler {
 
-  function scheduleAutomaticEmail($group, $event, $scheduling_condition = false, $subscriber_id = false, $meta = false) {
+  public function scheduleAutomaticEmail($group, $event, $scheduling_condition = false, $subscriber_id = false, $meta = false) {
     $newsletters = Scheduler::getNewsletters(Newsletter::TYPE_AUTOMATIC, $group);
     if (empty($newsletters)) return false;
     foreach ($newsletters as $newsletter) {
@@ -20,7 +20,7 @@ class AutomaticEmailScheduler {
     }
   }
 
-  function scheduleOrRescheduleAutomaticEmail($group, $event, $subscriber_id, $meta = false) {
+  public function scheduleOrRescheduleAutomaticEmail($group, $event, $subscriber_id, $meta = false) {
     $newsletters = Scheduler::getNewsletters(Newsletter::TYPE_AUTOMATIC, $group);
     if (empty($newsletters)) {
       return false;
@@ -41,7 +41,7 @@ class AutomaticEmailScheduler {
     }
   }
 
-  function rescheduleAutomaticEmail($group, $event, $subscriber_id) {
+  public function rescheduleAutomaticEmail($group, $event, $subscriber_id) {
     $newsletters = Scheduler::getNewsletters(Newsletter::TYPE_AUTOMATIC, $group);
     if (empty($newsletters)) {
       return false;
@@ -60,7 +60,7 @@ class AutomaticEmailScheduler {
     }
   }
 
-  function cancelAutomaticEmail($group, $event, $subscriber_id) {
+  public function cancelAutomaticEmail($group, $event, $subscriber_id) {
     $newsletters = Scheduler::getNewsletters(Newsletter::TYPE_AUTOMATIC, $group);
     if (empty($newsletters)) {
       return false;
@@ -81,7 +81,7 @@ class AutomaticEmailScheduler {
     }
   }
 
-  function createAutomaticEmailSendingTask($newsletter, $subscriber_id, $meta) {
+  public function createAutomaticEmailSendingTask($newsletter, $subscriber_id, $meta) {
     $sending_task = SendingTask::create();
     $sending_task->newsletter_id = $newsletter->id;
     if ($newsletter->sendTo === 'user' && $subscriber_id) {
diff --git a/lib/Newsletter/Scheduler/PostNotificationScheduler.php b/lib/Newsletter/Scheduler/PostNotificationScheduler.php
index 6936f7ba9e..d55137dd89 100644
--- a/lib/Newsletter/Scheduler/PostNotificationScheduler.php
+++ b/lib/Newsletter/Scheduler/PostNotificationScheduler.php
@@ -30,7 +30,7 @@ class PostNotificationScheduler {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function transitionHook($new_status, $old_status, $post) {
+  public function transitionHook($new_status, $old_status, $post) {
     $this->logger_factory->getLogger(LoggerFactory::TOPIC_POST_NOTIFICATIONS)->addInfo(
       'transition post notification hook initiated',
       [
@@ -46,7 +46,7 @@ class PostNotificationScheduler {
     $this->schedulePostNotification($post->ID);
   }
 
-  function schedulePostNotification($post_id) {
+  public function schedulePostNotification($post_id) {
     $this->logger_factory->getLogger(LoggerFactory::TOPIC_POST_NOTIFICATIONS)->addInfo(
       'schedule post notification hook',
       ['post_id' => $post_id]
@@ -63,7 +63,7 @@ class PostNotificationScheduler {
     }
   }
 
-  function createPostNotificationSendingTask($newsletter) {
+  public function createPostNotificationSendingTask($newsletter) {
     $existing_notification_history = Newsletter::tableAlias('newsletters')
       ->where('newsletters.parent_id', $newsletter->id)
       ->where('newsletters.type', Newsletter::TYPE_NOTIFICATION_HISTORY)
@@ -102,7 +102,7 @@ class PostNotificationScheduler {
     return $sending_task;
   }
 
-  function processPostNotificationSchedule($newsletter) {
+  public function processPostNotificationSchedule($newsletter) {
     $interval_type = $newsletter->intervalType;
     $hour = (int)$newsletter->timeOfDay / self::SECONDS_IN_HOUR;
     $week_day = $newsletter->weekDay;
diff --git a/lib/Newsletter/Scheduler/Scheduler.php b/lib/Newsletter/Scheduler/Scheduler.php
index 029d4858ed..b48b612861 100644
--- a/lib/Newsletter/Scheduler/Scheduler.php
+++ b/lib/Newsletter/Scheduler/Scheduler.php
@@ -8,7 +8,7 @@ use MailPoetVendor\Carbon\Carbon;
 
 class Scheduler {
 
-  static function getNextRunDate($schedule, $from_timestamp = false) {
+  public static function getNextRunDate($schedule, $from_timestamp = false) {
     $wp = new WPFunctions();
     $from_timestamp = ($from_timestamp) ? $from_timestamp : $wp->currentTime('timestamp');
     try {
@@ -21,7 +21,7 @@ class Scheduler {
     return $next_run_date;
   }
 
-  static function getPreviousRunDate($schedule, $from_timestamp = false) {
+  public static function getPreviousRunDate($schedule, $from_timestamp = false) {
     $wp = WPFunctions::get();
     $from_timestamp = ($from_timestamp) ? $from_timestamp : $wp->currentTime('timestamp');
     try {
@@ -34,7 +34,7 @@ class Scheduler {
     return $previous_run_date;
   }
 
-  static function getScheduledTimeWithDelay($after_time_type, $after_time_number) {
+  public static function getScheduledTimeWithDelay($after_time_type, $after_time_number) {
     $wp = WPFunctions::get();
     $current_time = Carbon::createFromTimestamp($wp->currentTime('timestamp'));
     switch ($after_time_type) {
@@ -51,7 +51,7 @@ class Scheduler {
     }
   }
 
-  static function getNewsletters($type, $group = false) {
+  public static function getNewsletters($type, $group = false) {
     return Newsletter::getPublished()
       ->filter('filterType', $type, $group)
       ->filter('filterStatus', Newsletter::STATUS_ACTIVE)
@@ -59,7 +59,7 @@ class Scheduler {
       ->findMany();
   }
 
-  static function formatDatetimeString($datetime_string) {
+  public static function formatDatetimeString($datetime_string) {
     return Carbon::parse($datetime_string)->format('Y-m-d H:i:s');
   }
 }
diff --git a/lib/Newsletter/Scheduler/WelcomeScheduler.php b/lib/Newsletter/Scheduler/WelcomeScheduler.php
index 2fb896a602..9578165308 100644
--- a/lib/Newsletter/Scheduler/WelcomeScheduler.php
+++ b/lib/Newsletter/Scheduler/WelcomeScheduler.php
@@ -10,7 +10,7 @@ class WelcomeScheduler {
 
   const WORDPRESS_ALL_ROLES = 'mailpoet_all';
 
-  function scheduleSubscriberWelcomeNotification($subscriber_id, $segments) {
+  public function scheduleSubscriberWelcomeNotification($subscriber_id, $segments) {
     $newsletters = Scheduler::getNewsletters(Newsletter::TYPE_WELCOME);
     if (empty($newsletters)) return false;
     $result = [];
@@ -24,7 +24,7 @@ class WelcomeScheduler {
     return $result;
   }
 
-  function scheduleWPUserWelcomeNotification(
+  public function scheduleWPUserWelcomeNotification(
     $subscriber_id,
     $wp_user,
     $old_user_data = false
@@ -52,7 +52,7 @@ class WelcomeScheduler {
     }
   }
 
-  function createWelcomeNotificationSendingTask($newsletter, $subscriber_id) {
+  public function createWelcomeNotificationSendingTask($newsletter, $subscriber_id) {
     $previously_scheduled_notification = SendingQueue::joinWithSubscribers()
       ->where('queues.newsletter_id', $newsletter->id)
       ->where('subscribers.subscriber_id', $subscriber_id)
diff --git a/lib/Newsletter/Shortcodes/Categories/Date.php b/lib/Newsletter/Shortcodes/Categories/Date.php
index cf9d26ce46..df058c6814 100644
--- a/lib/Newsletter/Shortcodes/Categories/Date.php
+++ b/lib/Newsletter/Shortcodes/Categories/Date.php
@@ -5,7 +5,7 @@ namespace MailPoet\Newsletter\Shortcodes\Categories;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Date {
-  static function process(
+  public static function process(
     $shortcode_details
   ) {
     $action_mapping = [
diff --git a/lib/Newsletter/Shortcodes/Categories/Link.php b/lib/Newsletter/Shortcodes/Categories/Link.php
index 4d86442576..b78595a1e8 100644
--- a/lib/Newsletter/Shortcodes/Categories/Link.php
+++ b/lib/Newsletter/Shortcodes/Categories/Link.php
@@ -11,7 +11,7 @@ use MailPoet\WP\Functions as WPFunctions;
 class Link {
   const CATEGORY_NAME = 'link';
 
-  static function process(
+  public static function process(
     $shortcode_details,
     $newsletter,
     $subscriber,
@@ -63,7 +63,7 @@ class Link {
     }
   }
 
-  static function processUrl($action, $url, $queue, $wp_user_preview = false) {
+  public static function processUrl($action, $url, $queue, $wp_user_preview = false) {
     if ($wp_user_preview) return $url;
     $settings = SettingsController::getInstance();
     return ($queue !== false && (boolean)$settings->get('tracking.enabled')) ?
@@ -71,7 +71,7 @@ class Link {
       $url;
   }
 
-  static function processShortcodeAction(
+  public static function processShortcodeAction(
     $shortcode_action, $newsletter, $subscriber, $queue, $wp_user_preview
   ) {
     $subscription_url_factory = SubscriptionUrlFactory::getInstance();
diff --git a/lib/Newsletter/Shortcodes/Categories/Newsletter.php b/lib/Newsletter/Shortcodes/Categories/Newsletter.php
index 3d96d9df4a..fe7d249653 100644
--- a/lib/Newsletter/Shortcodes/Categories/Newsletter.php
+++ b/lib/Newsletter/Shortcodes/Categories/Newsletter.php
@@ -7,7 +7,7 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoet\WP\Posts as WPPosts;
 
 class Newsletter {
-  static function process(
+  public static function process(
     $shortcode_details,
     $newsletter,
     $subscriber,
diff --git a/lib/Newsletter/Shortcodes/Categories/Subscriber.php b/lib/Newsletter/Shortcodes/Categories/Subscriber.php
index 76a55225c7..6a45a9d839 100644
--- a/lib/Newsletter/Shortcodes/Categories/Subscriber.php
+++ b/lib/Newsletter/Shortcodes/Categories/Subscriber.php
@@ -10,7 +10,7 @@ class Subscriber {
   /**
    * @param \MailPoet\Models\Subscriber|false|mixed $subscriber
    */
-  static function process(
+  public static function process(
     $shortcode_details,
     $newsletter,
     $subscriber
diff --git a/lib/Newsletter/Shortcodes/Shortcodes.php b/lib/Newsletter/Shortcodes/Shortcodes.php
index cbaa33d5d4..43adf1c766 100644
--- a/lib/Newsletter/Shortcodes/Shortcodes.php
+++ b/lib/Newsletter/Shortcodes/Shortcodes.php
@@ -11,7 +11,7 @@ class Shortcodes {
   public $wp_user_preview;
   const SHORTCODE_CATEGORY_NAMESPACE = 'MailPoet\Newsletter\Shortcodes\Categories\\';
 
-  function __construct(
+  public function __construct(
     $newsletter = false,
     $subscriber = false,
     $queue = false,
@@ -23,7 +23,7 @@ class Shortcodes {
     $this->wp_user_preview = $wp_user_preview;
   }
 
-  function extract($content, $categories = false) {
+  public function extract($content, $categories = false) {
     $categories = (is_array($categories)) ? implode('|', $categories) : false;
     // match: [category:shortcode] or [category|category|...:shortcode]
     // dot not match: [category://shortcode] - avoids matching http/ftp links
@@ -38,7 +38,7 @@ class Shortcodes {
       false;
   }
 
-  function match($shortcode) {
+  public function match($shortcode) {
     preg_match(
       '/\[(?P<category>\w+)?:(?P<action>\w+)(?:.*?\|.*?(?P<argument>\w+):(?P<argument_value>.*?))?\]/',
       $shortcode,
@@ -47,7 +47,7 @@ class Shortcodes {
     return $match;
   }
 
-  function process($shortcodes, $content = false) {
+  public function process($shortcodes, $content = false) {
     $_this = $this;
     $processed_shortcodes = array_map(
       function($shortcode) use ($content, $_this) {
@@ -93,7 +93,7 @@ class Shortcodes {
     return $processed_shortcodes;
   }
 
-  function replace($content, $content_source = null, $categories = null) {
+  public function replace($content, $content_source = null, $categories = null) {
     $shortcodes = $this->extract($content, $categories);
     if (!$shortcodes) {
       return $content;
diff --git a/lib/Newsletter/Shortcodes/ShortcodesHelper.php b/lib/Newsletter/Shortcodes/ShortcodesHelper.php
index 7d1bb90100..3df2101c54 100644
--- a/lib/Newsletter/Shortcodes/ShortcodesHelper.php
+++ b/lib/Newsletter/Shortcodes/ShortcodesHelper.php
@@ -8,7 +8,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class ShortcodesHelper {
 
-  static function getShortcodes() {
+  public static function getShortcodes() {
     $shortcodes = [
       WPFunctions::get()->__('Subscriber', 'mailpoet') => [
         [
@@ -115,7 +115,7 @@ class ShortcodesHelper {
     return $shortcodes;
   }
 
-  static function getCustomFields() {
+  public static function getCustomFields() {
     $custom_fields = CustomField::findMany();
     if (!$custom_fields) return false;
     return array_map(function($custom_field) {
diff --git a/lib/Newsletter/Statistics/NewsletterStatistics.php b/lib/Newsletter/Statistics/NewsletterStatistics.php
index 76e2e0f02b..e76cb8e029 100644
--- a/lib/Newsletter/Statistics/NewsletterStatistics.php
+++ b/lib/Newsletter/Statistics/NewsletterStatistics.php
@@ -16,7 +16,7 @@ class NewsletterStatistics {
   /** @var int */
   private $total_sent_count;
 
-  function __construct($click_count, $open_count, $unsubscribe_count, $total_sent_count) {
+  public function __construct($click_count, $open_count, $unsubscribe_count, $total_sent_count) {
     $this->click_count = $click_count;
     $this->open_count = $open_count;
     $this->unsubscribe_count = $unsubscribe_count;
diff --git a/lib/Newsletter/Statistics/NewsletterStatisticsRepository.php b/lib/Newsletter/Statistics/NewsletterStatisticsRepository.php
index aab3544dec..d3367b63db 100644
--- a/lib/Newsletter/Statistics/NewsletterStatisticsRepository.php
+++ b/lib/Newsletter/Statistics/NewsletterStatisticsRepository.php
@@ -19,7 +19,7 @@ class NewsletterStatisticsRepository extends Repository {
    * @param NewsletterEntity $newsletter
    * @return int
    */
-  function getTotalSentCount(NewsletterEntity $newsletter) {
+  public function getTotalSentCount(NewsletterEntity $newsletter) {
     try {
       return (int)$this->doctrine_repository
         ->createQueryBuilder('n')
@@ -41,7 +41,7 @@ class NewsletterStatisticsRepository extends Repository {
    * @param NewsletterEntity $newsletter
    * @return NewsletterStatistics
    */
-  function getStatistics(NewsletterEntity $newsletter) {
+  public function getStatistics(NewsletterEntity $newsletter) {
     return new NewsletterStatistics(
       $this->getStatisticsClickCount($newsletter),
       $this->getStatisticsOpenCount($newsletter),
@@ -54,7 +54,7 @@ class NewsletterStatisticsRepository extends Repository {
    * @param NewsletterEntity $newsletter
    * @return int
    */
-  function getStatisticsClickCount(NewsletterEntity $newsletter) {
+  public function getStatisticsClickCount(NewsletterEntity $newsletter) {
     return $this->getStatisticsCount($newsletter, StatisticsClickEntity::class);
   }
 
@@ -62,7 +62,7 @@ class NewsletterStatisticsRepository extends Repository {
    * @param NewsletterEntity $newsletter
    * @return int
    */
-  function getStatisticsOpenCount(NewsletterEntity $newsletter) {
+  public function getStatisticsOpenCount(NewsletterEntity $newsletter) {
     return $this->getStatisticsCount($newsletter, StatisticsOpenEntity::class);
   }
 
@@ -70,7 +70,7 @@ class NewsletterStatisticsRepository extends Repository {
    * @param NewsletterEntity $newsletter
    * @return int
    */
-  function getStatisticsUnsubscribeCount(NewsletterEntity $newsletter) {
+  public function getStatisticsUnsubscribeCount(NewsletterEntity $newsletter) {
     return $this->getStatisticsCount($newsletter, StatisticsUnsubscribeEntity::class);
   }
 
diff --git a/lib/Newsletter/Url.php b/lib/Newsletter/Url.php
index 91bb80d217..91a7dd1b3b 100644
--- a/lib/Newsletter/Url.php
+++ b/lib/Newsletter/Url.php
@@ -11,7 +11,7 @@ class Url {
   const TYPE_ARCHIVE = 'display_archive';
   const TYPE_LISTING_EDITOR = 'display_listing_editor';
 
-  static function getViewInBrowserUrl(
+  public static function getViewInBrowserUrl(
     $type,
     $newsletter,
     $subscriber = false,
@@ -45,7 +45,7 @@ class Url {
     );
   }
 
-  static function createUrlDataObject($newsletter, $subscriber, $queue, $preview) {
+  public static function createUrlDataObject($newsletter, $subscriber, $queue, $preview) {
     return [
       (!empty($newsletter->id)) ?
         (int)$newsletter->id :
@@ -66,7 +66,7 @@ class Url {
     ];
   }
 
-  static function transformUrlDataObject($data) {
+  public static function transformUrlDataObject($data) {
     reset($data);
     if (!is_int(key($data))) return $data;
     $transformed_data = [];
diff --git a/lib/Newsletter/ViewInBrowser.php b/lib/Newsletter/ViewInBrowser.php
index 693a516ea6..9df82852ff 100644
--- a/lib/Newsletter/ViewInBrowser.php
+++ b/lib/Newsletter/ViewInBrowser.php
@@ -14,12 +14,12 @@ class ViewInBrowser {
   /** @var bool */
   private $is_tracking_enabled;
 
-  function __construct(Emoji $emoji, $is_tracking_enabled) {
+  public function __construct(Emoji $emoji, $is_tracking_enabled) {
     $this->is_tracking_enabled = $is_tracking_enabled;
     $this->emoji = $emoji;
   }
 
-  function view($data) {
+  public function view($data) {
     $wp_user_preview = (
       ($data->subscriber && $data->subscriber->isWPUser() && $data->preview) ||
       ($data->preview && $data->newsletter_hash)
@@ -32,7 +32,7 @@ class ViewInBrowser {
     );
   }
 
-  function renderNewsletter($newsletter, $subscriber, $queue, $wp_user_preview) {
+  public function renderNewsletter($newsletter, $subscriber, $queue, $wp_user_preview) {
     if ($queue && $queue->getNewsletterRenderedBody()) {
       $newsletter_body = $queue->getNewsletterRenderedBody('html');
       $newsletter_body = $this->emoji->decodeEmojisInBody($newsletter_body);
diff --git a/lib/Referrals/ReferralDetector.php b/lib/Referrals/ReferralDetector.php
index 5718cf4753..27ade9d984 100644
--- a/lib/Referrals/ReferralDetector.php
+++ b/lib/Referrals/ReferralDetector.php
@@ -15,12 +15,12 @@ class ReferralDetector {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(WPFunctions $wp, SettingsController $settings) {
+  public function __construct(WPFunctions $wp, SettingsController $settings) {
     $this->wp = $wp;
     $this->settings = $settings;
   }
 
-  function detect() {
+  public function detect() {
     $referral_id = $this->settings->get(self::REFERRAL_SETTING_NAME, null);
     if ($referral_id) {
       return $referral_id;
diff --git a/lib/Referrals/UrlDecorator.php b/lib/Referrals/UrlDecorator.php
index 4546e3d06c..edf0657214 100644
--- a/lib/Referrals/UrlDecorator.php
+++ b/lib/Referrals/UrlDecorator.php
@@ -13,12 +13,12 @@ class UrlDecorator {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(WPFunctions $wp, SettingsController $settings) {
+  public function __construct(WPFunctions $wp, SettingsController $settings) {
     $this->wp = $wp;
     $this->settings = $settings;
   }
 
-  function decorate($url) {
+  public function decorate($url) {
     $referral_id = $this->settings->get(ReferralDetector::REFERRAL_SETTING_NAME, null);
     if ($referral_id === null) {
       return $url;
diff --git a/lib/Router/Endpoints/CronDaemon.php b/lib/Router/Endpoints/CronDaemon.php
index 4546787df6..059c468e18 100644
--- a/lib/Router/Endpoints/CronDaemon.php
+++ b/lib/Router/Endpoints/CronDaemon.php
@@ -27,20 +27,20 @@ class CronDaemon {
   /** @var CronHelper */
   private $cron_helper;
 
-  function __construct(DaemonHttpRunner $daemon_runner, CronHelper $cron_helper) {
+  public function __construct(DaemonHttpRunner $daemon_runner, CronHelper $cron_helper) {
     $this->daemon_runner = $daemon_runner;
     $this->cron_helper = $cron_helper;
   }
 
-  function run($data) {
+  public function run($data) {
     $this->daemon_runner->run($data);
   }
 
-  function ping() {
+  public function ping() {
      die($this->cron_helper->pingDaemon());
   }
 
-  function pingResponse() {
+  public function pingResponse() {
     $this->daemon_runner->ping();
   }
 }
diff --git a/lib/Router/Endpoints/Subscription.php b/lib/Router/Endpoints/Subscription.php
index ddab58f2c7..e72b9f15e4 100644
--- a/lib/Router/Endpoints/Subscription.php
+++ b/lib/Router/Endpoints/Subscription.php
@@ -26,15 +26,15 @@ class Subscription {
   /** @var UserSubscription\Pages */
   private $subscription_pages;
 
-  function __construct(UserSubscription\Pages $subscription_pages) {
+  public function __construct(UserSubscription\Pages $subscription_pages) {
     $this->subscription_pages = $subscription_pages;
   }
 
-  function captcha($data) {
+  public function captcha($data) {
     $this->initSubscriptionPage(UserSubscription\Pages::ACTION_CAPTCHA, $data);
   }
 
-  function captchaImage($data) {
+  public function captchaImage($data) {
     $captcha = new UserSubscription\Captcha;
     $width = !empty($data['width']) ? (int)$data['width'] : null;
     $height = !empty($data['height']) ? (int)$data['height'] : null;
@@ -42,16 +42,16 @@ class Subscription {
     return $captcha->renderImage($width, $height, $session_id);
   }
 
-  function confirm($data) {
+  public function confirm($data) {
     $subscription = $this->initSubscriptionPage(UserSubscription\Pages::ACTION_CONFIRM, $data);
     $subscription->confirm();
   }
 
-  function manage($data) {
+  public function manage($data) {
     $this->initSubscriptionPage(UserSubscription\Pages::ACTION_MANAGE, $data);
   }
 
-  function unsubscribe($data) {
+  public function unsubscribe($data) {
     $subscription = $this->initSubscriptionPage(UserSubscription\Pages::ACTION_UNSUBSCRIBE, $data);
     $subscription->unsubscribe();
   }
diff --git a/lib/Router/Endpoints/Track.php b/lib/Router/Endpoints/Track.php
index bd1e243957..515eed9173 100644
--- a/lib/Router/Endpoints/Track.php
+++ b/lib/Router/Endpoints/Track.php
@@ -41,15 +41,15 @@ class Track {
     $this->link_tokens = $link_tokens;
   }
 
-  function click($data) {
+  public function click($data) {
     return $this->clicks->track($this->_processTrackData($data));
   }
 
-  function open($data) {
+  public function open($data) {
     return $this->opens->track($this->_processTrackData($data));
   }
 
-  function _processTrackData($data) {
+  public function _processTrackData($data) {
     $data = (object)Links::transformUrlDataObject($data);
     if (empty($data->queue_id) ||
       empty($data->subscriber_id) ||
@@ -73,7 +73,7 @@ class Track {
     return $this->_validateTrackData($data);
   }
 
-  function _validateTrackData($data) {
+  public function _validateTrackData($data) {
     if (!$data->subscriber || !$data->queue || !$data->newsletter) return false;
     $subscriber_token_match = $this->link_tokens->verifyToken($data->subscriber, $data->subscriber_token);
     if (!$subscriber_token_match) {
@@ -89,7 +89,7 @@ class Track {
       false;
   }
 
-  function terminate($code) {
+  public function terminate($code) {
     WPFunctions::get()->statusHeader($code);
     WPFunctions::get()->getTemplatePart((string)$code);
     exit;
diff --git a/lib/Router/Endpoints/ViewInBrowser.php b/lib/Router/Endpoints/ViewInBrowser.php
index 16da1853aa..8b2fdebb08 100644
--- a/lib/Router/Endpoints/ViewInBrowser.php
+++ b/lib/Router/Endpoints/ViewInBrowser.php
@@ -32,20 +32,20 @@ class ViewInBrowser {
   /** @var Emoji */
   private $emoji;
 
-  function __construct(AccessControl $access_control, SettingsController $settings, LinkTokens $link_tokens, Emoji $emoji) {
+  public function __construct(AccessControl $access_control, SettingsController $settings, LinkTokens $link_tokens, Emoji $emoji) {
     $this->access_control = $access_control;
     $this->settings = $settings;
     $this->link_tokens = $link_tokens;
     $this->emoji = $emoji;
   }
 
-  function view($data) {
+  public function view($data) {
     $data = $this->_processBrowserPreviewData($data);
     $view_in_browser = new NewsletterViewInBrowser($this->emoji, (bool)$this->settings->get('tracking.enabled'));
     return $this->_displayNewsletter($view_in_browser->view($data));
   }
 
-  function _processBrowserPreviewData($data) {
+  public function _processBrowserPreviewData($data) {
     $data = (object)NewsletterUrl::transformUrlDataObject($data);
     return ($this->_validateBrowserPreviewData($data)) ?
       $data :
@@ -56,7 +56,7 @@ class ViewInBrowser {
    * @param \stdClass $data
    * @return bool|\stdClass
    */
-  function _validateBrowserPreviewData($data) {
+  public function _validateBrowserPreviewData($data) {
     // either newsletter ID or hash must be defined, and newsletter must exist
     if (empty($data->newsletter_id) && empty($data->newsletter_hash)) return false;
     $data->newsletter = (!empty($data->newsletter_hash)) ?
@@ -113,13 +113,13 @@ class ViewInBrowser {
     return $data;
   }
 
-  function _displayNewsletter($result) {
+  public function _displayNewsletter($result) {
     header('Content-Type: text/html; charset=utf-8');
     echo $result;
     exit;
   }
 
-  function _abort() {
+  public function _abort() {
     WPFunctions::get()->statusHeader(404);
     exit;
   }
diff --git a/lib/Router/Router.php b/lib/Router/Router.php
index baa8a24728..838d5bfc0c 100644
--- a/lib/Router/Router.php
+++ b/lib/Router/Router.php
@@ -20,7 +20,7 @@ class Router {
   const RESPONSE_ERROR = 404;
   const RESPONE_FORBIDDEN = 403;
 
-  function __construct(AccessControl $access_control, ContainerInterface $container, $api_data = false) {
+  public function __construct(AccessControl $access_control, ContainerInterface $container, $api_data = false) {
     $api_data = ($api_data) ? $api_data : $_GET;
     $this->api_request = is_array($api_data) && array_key_exists(self::NAME, $api_data);
     $this->endpoint = isset($api_data['endpoint']) ?
@@ -36,7 +36,7 @@ class Router {
     $this->container = $container;
   }
 
-  function init() {
+  public function init() {
     if (!$this->api_request) return;
     $endpoint_class = __NAMESPACE__ . "\\Endpoints\\" . ucfirst($this->endpoint);
 
@@ -62,7 +62,7 @@ class Router {
     }
   }
 
-  static function decodeRequestData($data) {
+  public static function decodeRequestData($data) {
     $data = json_decode(base64_decode($data), true);
     if (!is_array($data)) {
       $data = [];
@@ -70,11 +70,11 @@ class Router {
     return $data;
   }
 
-  static function encodeRequestData($data) {
+  public static function encodeRequestData($data) {
     return rtrim(base64_encode(json_encode($data)), '=');
   }
 
-  static function buildRequest($endpoint, $action, $data = false) {
+  public static function buildRequest($endpoint, $action, $data = false) {
     $params = [
       self::NAME => '',
       'endpoint' => $endpoint,
@@ -86,12 +86,12 @@ class Router {
     return WPFunctions::get()->addQueryArg($params, WPFunctions::get()->homeUrl());
   }
 
-  function terminateRequest($code, $message) {
+  public function terminateRequest($code, $message) {
     WPFunctions::get()->statusHeader($code, $message);
     exit;
   }
 
-  function validatePermissions($endpoint_action, $permissions) {
+  public function validatePermissions($endpoint_action, $permissions) {
     // validate action permission if defined, otherwise validate global permission
     return(!empty($permissions['actions'][$endpoint_action])) ?
       $this->access_control->validatePermission($permissions['actions'][$endpoint_action]) :
diff --git a/lib/Segments/BulkAction.php b/lib/Segments/BulkAction.php
index 8b4bfae384..fe886b71f3 100644
--- a/lib/Segments/BulkAction.php
+++ b/lib/Segments/BulkAction.php
@@ -12,7 +12,7 @@ class BulkAction {
   private $data = null;
   private $wp;
 
-  function __construct($data) {
+  public function __construct($data) {
     $this->data = $data;
     $this->wp = new WPFunctions;
   }
@@ -21,7 +21,7 @@ class BulkAction {
    * @return array
    * @throws \Exception
    */
-  function apply() {
+  public function apply() {
     if (!isset($this->data['listing']['filter']['segment'])) {
       throw new \InvalidArgumentException('Missing segment id');
     }
diff --git a/lib/Segments/SubscribersFinder.php b/lib/Segments/SubscribersFinder.php
index e4bb05758f..4a10bd458f 100644
--- a/lib/Segments/SubscribersFinder.php
+++ b/lib/Segments/SubscribersFinder.php
@@ -16,14 +16,14 @@ class SubscribersFinder {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp = null) {
+  public function __construct(WPFunctions $wp = null) {
     if (!$wp) {
       $wp = new WPFunctions;
     }
     $this->wp = $wp;
   }
 
-  function findSubscribersInSegments($subscribers_to_process_ids, $newsletter_segments_ids) {
+  public function findSubscribersInSegments($subscribers_to_process_ids, $newsletter_segments_ids) {
     $result = [];
     foreach ($newsletter_segments_ids as $segment_id) {
       $segment = Segment::findOne($segment_id);
@@ -54,7 +54,7 @@ class SubscribersFinder {
     return in_array($segment->type, [Segment::TYPE_DEFAULT, Segment::TYPE_WP_USERS, Segment::TYPE_WC_USERS], true);
   }
 
-  function addSubscribersToTaskFromSegments(ScheduledTask $task, array $segments) {
+  public function addSubscribersToTaskFromSegments(ScheduledTask $task, array $segments) {
     // Prepare subscribers on the DB side for performance reasons
     $staticSegments = [];
     $dynamicSegments = [];
diff --git a/lib/Segments/SubscribersListings.php b/lib/Segments/SubscribersListings.php
index aa94eefcb0..54470238cc 100644
--- a/lib/Segments/SubscribersListings.php
+++ b/lib/Segments/SubscribersListings.php
@@ -13,12 +13,12 @@ class SubscribersListings {
 
   private $wp;
 
-  function __construct(Handler $handler, WPFunctions $wp) {
+  public function __construct(Handler $handler, WPFunctions $wp) {
     $this->handler = $handler;
     $this->wp = $wp;
   }
 
-  function getListingsInSegment($data) {
+  public function getListingsInSegment($data) {
     if (!isset($data['filter']['segment'])) {
       throw new \InvalidArgumentException('Missing segment id');
     }
diff --git a/lib/Segments/WP.php b/lib/Segments/WP.php
index 244349c223..3f1b8b1679 100644
--- a/lib/Segments/WP.php
+++ b/lib/Segments/WP.php
@@ -14,7 +14,7 @@ use MailPoet\Subscribers\Source;
 use MailPoetVendor\Idiorm\ORM;
 
 class WP {
-  static function synchronizeUser($wp_user_id, $old_wp_user_data = false) {
+  public static function synchronizeUser($wp_user_id, $old_wp_user_data = false) {
     $wp_user = \get_userdata($wp_user_id);
     $wp_segment = Segment::getWPSegment();
 
@@ -85,7 +85,7 @@ class WP {
     }
   }
 
-  static function synchronizeUsers() {
+  public static function synchronizeUsers() {
 
     $updated_users_emails = self::updateSubscribersEmails();
     $inserted_users_emails = self::insertSubscribers();
@@ -238,8 +238,8 @@ class WP {
     global $wpdb;
     $query = '
       UPDATE %s as subscribers
-      LEFT JOIN %s as clicks ON subscribers.id=clicks.subscriber_id 
-      LEFT JOIN %s as opens ON subscribers.id=opens.subscriber_id 
+      LEFT JOIN %s as clicks ON subscribers.id=clicks.subscriber_id
+      LEFT JOIN %s as opens ON subscribers.id=opens.subscriber_id
       JOIN %s as usermeta ON usermeta.user_id=subscribers.wp_user_id AND usermeta.meta_key = "default_password_nag" AND usermeta.meta_value = "1"
       SET `status` = "unconfirmed"
       WHERE `wp_user_id` IS NOT NULL AND `status` = "subscribed" AND `confirmed_at` IS NULL AND clicks.id IS NULL AND opens.id IS NULL
diff --git a/lib/Segments/WooCommerce.php b/lib/Segments/WooCommerce.php
index b062734db5..99aa6b9b78 100644
--- a/lib/Segments/WooCommerce.php
+++ b/lib/Segments/WooCommerce.php
@@ -22,12 +22,12 @@ class WooCommerce {
   private $mailpoet_email_collation;
   private $wp_postmeta_value_collation;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function synchronizeRegisteredCustomer($wp_user_id, $current_filter = null) {
+  public function synchronizeRegisteredCustomer($wp_user_id, $current_filter = null) {
     $wc_segment = Segment::getWooCommerceSegment();
 
     if ($wc_segment === false) return;
@@ -75,7 +75,7 @@ class WooCommerce {
     return true;
   }
 
-  function synchronizeGuestCustomer($order_id, $current_filter = null) {
+  public function synchronizeGuestCustomer($order_id, $current_filter = null) {
     $wc_order = $this->wp->getPost($order_id);
     $wc_segment = Segment::getWooCommerceSegment();
 
@@ -97,7 +97,7 @@ class WooCommerce {
     }
   }
 
-  function synchronizeCustomers() {
+  public function synchronizeCustomers() {
     $this->getColumnCollation();
 
     WP::synchronizeUsers(); // synchronize registered users
diff --git a/lib/Services/AuthorizedEmailsController.php b/lib/Services/AuthorizedEmailsController.php
index cfd639a739..90e0478b35 100644
--- a/lib/Services/AuthorizedEmailsController.php
+++ b/lib/Services/AuthorizedEmailsController.php
@@ -23,12 +23,12 @@ class AuthorizedEmailsController {
     Newsletter::TYPE_AUTOMATIC,
   ];
 
-  function __construct(SettingsController $settingsController, Bridge $bridge) {
+  public function __construct(SettingsController $settingsController, Bridge $bridge) {
     $this->settings = $settingsController;
     $this->bridge = $bridge;
   }
 
-  function checkAuthorizedEmailAddresses() {
+  public function checkAuthorizedEmailAddresses() {
     if (!Bridge::isMPSendingServiceEnabled()) {
       $this->settings->set(self::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING, null);
       $this->updateMailerLog();
@@ -49,14 +49,14 @@ class AuthorizedEmailsController {
     $this->updateMailerLog($result);
   }
 
-  function onSettingsSave($settings) {
+  public function onSettingsSave($settings) {
     $sender_address_set = !empty($settings['sender']['address']);
     if ($sender_address_set) {
       $this->checkAuthorizedEmailAddresses();
     }
   }
 
-  function onNewsletterUpdate(Newsletter $newsletter, Newsletter $old_newsletter = null) {
+  public function onNewsletterUpdate(Newsletter $newsletter, Newsletter $old_newsletter = null) {
     if ($old_newsletter === null || $newsletter->sender_address === $old_newsletter->sender_address) {
       return;
     }
diff --git a/lib/Services/Bridge.php b/lib/Services/Bridge.php
index 9e0291d1e2..bcb8e4ef96 100644
--- a/lib/Services/Bridge.php
+++ b/lib/Services/Bridge.php
@@ -36,14 +36,14 @@ class Bridge {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(SettingsController $settingsController = null) {
+  public function __construct(SettingsController $settingsController = null) {
     if ($settingsController === null) {
       $settingsController = SettingsController::getInstance();
     }
     $this->settings = $settingsController;
   }
 
-  static function isMPSendingServiceEnabled() {
+  public static function isMPSendingServiceEnabled() {
     try {
       $mailer_config = SettingsController::getInstance()->get(Mailer::MAILER_CONFIG_SETTING_NAME);
       return !empty($mailer_config['method'])
@@ -53,19 +53,19 @@ class Bridge {
     }
   }
 
-  static function isMSSKeySpecified() {
+  public static function isMSSKeySpecified() {
     $settings = SettingsController::getInstance();
     $key = $settings->get(self::API_KEY_SETTING_NAME);
     return !empty($key);
   }
 
-  static function isPremiumKeySpecified() {
+  public static function isPremiumKeySpecified() {
     $settings = SettingsController::getInstance();
     $key = $settings->get(self::PREMIUM_KEY_SETTING_NAME);
     return !empty($key);
   }
 
-  static function pingBridge() {
+  public static function pingBridge() {
     $params = [
       'blocking' => true,
       'timeout' => 10,
@@ -75,7 +75,7 @@ class Bridge {
     return $wp->wpRemoteRetrieveResponseCode($result) === 200;
   }
 
-  function initApi($api_key) {
+  public function initApi($api_key) {
     if ($this->api) {
       $this->api->setKey($api_key);
     } else {
@@ -93,20 +93,20 @@ class Bridge {
     return $this->api;
   }
 
-  function getAuthorizedEmailAddresses() {
+  public function getAuthorizedEmailAddresses() {
     return $this
       ->getApi($this->settings->get(self::API_KEY_SETTING_NAME))
       ->getAuthorizedEmailAddresses();
   }
 
-  function checkMSSKey($api_key) {
+  public function checkMSSKey($api_key) {
     $result = $this
       ->getApi($api_key)
       ->checkMSSKey();
     return $this->processKeyCheckResult($result);
   }
 
-  function storeMSSKeyAndState($key, $state) {
+  public function storeMSSKeyAndState($key, $state) {
     if (empty($state['state'])
       || $state['state'] === self::KEY_CHECK_ERROR
     ) {
@@ -126,7 +126,7 @@ class Bridge {
     );
   }
 
-  function checkPremiumKey($key) {
+  public function checkPremiumKey($key) {
     $result = $this
       ->getApi($key)
       ->checkPremiumKey();
@@ -159,7 +159,7 @@ class Bridge {
     );
   }
 
-  function storePremiumKeyAndState($key, $state) {
+  public function storePremiumKeyAndState($key, $state) {
     if (empty($state['state'])
       || $state['state'] === self::KEY_CHECK_ERROR
     ) {
@@ -189,7 +189,7 @@ class Bridge {
     return $state;
   }
 
-  function updateSubscriberCount($result) {
+  public function updateSubscriberCount($result) {
     if (
       (
         !empty($result['state'])
@@ -205,7 +205,7 @@ class Bridge {
     return null;
   }
 
-  static function invalidateKey() {
+  public static function invalidateKey() {
     $settings = SettingsController::getInstance();
     $settings->set(
       self::API_KEY_STATE_SETTING_NAME,
@@ -213,7 +213,7 @@ class Bridge {
     );
   }
 
-  function onSettingsSave($settings) {
+  public function onSettingsSave($settings) {
     $api_key_set = !empty($settings[Mailer::MAILER_CONFIG_SETTING_NAME]['mailpoet_api_key']);
     $premium_key_set = !empty($settings['premium']['premium_key']);
     if ($api_key_set) {
diff --git a/lib/Services/Bridge/API.php b/lib/Services/Bridge/API.php
index 02910e2b14..079591949e 100644
--- a/lib/Services/Bridge/API.php
+++ b/lib/Services/Bridge/API.php
@@ -32,7 +32,7 @@ class API {
   public $url_stats = 'https://bridge.mailpoet.com/api/v0/stats';
   public $url_authorized_email_addresses = 'https://bridge.mailpoet.com/api/v0/authorized_email_addresses';
 
-  function __construct($api_key, $wp = null) {
+  public function __construct($api_key, $wp = null) {
     $this->setKey($api_key);
     if (is_null($wp)) {
       $this->wp = new WPFunctions();
@@ -42,7 +42,7 @@ class API {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function checkMSSKey() {
+  public function checkMSSKey() {
     $result = $this->request(
       $this->url_me,
       ['site' => WPFunctions::get()->homeUrl()]
@@ -61,7 +61,7 @@ class API {
     return ['code' => $code, 'data' => $body];
   }
 
-  function checkPremiumKey() {
+  public function checkPremiumKey() {
     $result = $this->request(
       $this->url_premium,
       ['site' => WPFunctions::get()->homeUrl()]
@@ -83,14 +83,14 @@ class API {
     return ['code' => $code, 'data' => $body];
   }
 
-  function logCurlInformation($headers, $info) {
+  public function logCurlInformation($headers, $info) {
     $this->logger_factory->getLogger(LoggerFactory::TOPIC_MSS)->addInfo(
       'requests-curl.after_request',
       ['headers' => $headers, 'curl_info' => $info]
     );
   }
 
-  function sendMessages($message_body) {
+  public function sendMessages($message_body) {
     add_action('requests-curl.after_request', [$this, 'logCurlInformation'], 10, 2);
     $result = $this->request(
       $this->url_messages,
@@ -118,7 +118,7 @@ class API {
     return ['status' => self::SENDING_STATUS_OK];
   }
 
-  function checkBounces(array $emails) {
+  public function checkBounces(array $emails) {
     $result = $this->request(
       $this->url_bounces,
       $emails
@@ -129,7 +129,7 @@ class API {
     return false;
   }
 
-  function updateSubscriberCount($count) {
+  public function updateSubscriberCount($count) {
     $result = $this->request(
       $this->url_stats,
       ['subscriber_count' => (int)$count],
@@ -138,7 +138,7 @@ class API {
     return $this->wp->wpRemoteRetrieveResponseCode($result) === self::RESPONSE_CODE_STATS_SAVED;
   }
 
-  function getAuthorizedEmailAddresses() {
+  public function getAuthorizedEmailAddresses() {
     $result = $this->request(
       $this->url_authorized_email_addresses,
       null,
@@ -150,11 +150,11 @@ class API {
     return false;
   }
 
-  function setKey($api_key) {
+  public function setKey($api_key) {
     $this->api_key = $api_key;
   }
 
-  function getKey() {
+  public function getKey() {
     return $this->api_key;
   }
 
diff --git a/lib/Services/Release/API.php b/lib/Services/Release/API.php
index de2d12fd98..76e73510ec 100644
--- a/lib/Services/Release/API.php
+++ b/lib/Services/Release/API.php
@@ -9,12 +9,12 @@ class API {
   private $wp;
   public $url_products = 'https://release.mailpoet.com/products/';
 
-  function __construct($api_key) {
+  public function __construct($api_key) {
     $this->setKey($api_key);
     $this->wp = new WPFunctions();
   }
 
-  function getPluginInformation($plugin_name) {
+  public function getPluginInformation($plugin_name) {
     $result = $this->request(
       $this->url_products . $plugin_name
     );
@@ -35,11 +35,11 @@ class API {
     return $body;
   }
 
-  function setKey($api_key) {
+  public function setKey($api_key) {
     $this->api_key = $api_key;
   }
 
-  function getKey() {
+  public function getKey() {
     return $this->api_key;
   }
 
diff --git a/lib/Services/SPFCheck.php b/lib/Services/SPFCheck.php
index f9d5559f17..314587f614 100644
--- a/lib/Services/SPFCheck.php
+++ b/lib/Services/SPFCheck.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Services;
 
 class SPFCheck {
-  function checkSPFRecord($domain) {
+  public function checkSPFRecord($domain) {
     $record = $this->getSPFRecord($domain);
     if (empty($record)) {
       return true;
diff --git a/lib/Settings/Charsets.php b/lib/Settings/Charsets.php
index 087ce97b42..5b79eaf687 100644
--- a/lib/Settings/Charsets.php
+++ b/lib/Settings/Charsets.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Settings;
 
 class Charsets {
-  static function getAll() {
+  public static function getAll() {
     return [
       'UTF-8', 'UTF-7', 'BIG5', 'ISO-2022-JP',
       'ISO-8859-1', 'ISO-8859-2', 'ISO-8859-3',
diff --git a/lib/Settings/Hosts.php b/lib/Settings/Hosts.php
index fc60957fca..15e86eda92 100644
--- a/lib/Settings/Hosts.php
+++ b/lib/Settings/Hosts.php
@@ -212,11 +212,11 @@ class Hosts {
     ],
   ];
 
-  static function getWebHosts() {
+  public static function getWebHosts() {
     return static::$_web;
   }
 
-  static function getSMTPHosts() {
+  public static function getSMTPHosts() {
     return static::$_smtp;
   }
 }
\ No newline at end of file
diff --git a/lib/Settings/Pages.php b/lib/Settings/Pages.php
index dda8c1d9dc..ad5ec0589d 100644
--- a/lib/Settings/Pages.php
+++ b/lib/Settings/Pages.php
@@ -6,10 +6,10 @@ use MailPoet\Subscription;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Pages {
-  function __construct() {
+  public function __construct() {
   }
 
-  function init() {
+  public function init() {
     WPFunctions::get()->registerPostType('mailpoet_page', [
       'labels' => [
         'name' => WPFunctions::get()->__('MailPoet Page', 'mailpoet'),
@@ -27,7 +27,7 @@ class Pages {
     ]);
   }
 
-  static function createMailPoetPage() {
+  public static function createMailPoetPage() {
     WPFunctions::get()->removeAllActions('pre_post_update');
     WPFunctions::get()->removeAllActions('save_post');
     WPFunctions::get()->removeAllActions('wp_insert_post');
@@ -44,7 +44,7 @@ class Pages {
     return ((int)$id > 0) ? (int)$id : false;
   }
 
-  static function getMailPoetPages() {
+  public static function getMailPoetPages() {
     return WPFunctions::get()->getPosts([
       'post_type' => 'mailpoet_page',
     ]);
@@ -55,7 +55,7 @@ class Pages {
    *
    * @return bool
    */
-  static function isMailpoetPage($id) {
+  public static function isMailpoetPage($id) {
     $mailpoetPages = static::getMailPoetPages();
     foreach ($mailpoetPages as $mailpoetPage) {
       if ($mailpoetPage->ID === $id) {
@@ -65,7 +65,7 @@ class Pages {
     return false;
   }
 
-  static function getAll() {
+  public static function getAll() {
     $all_pages = array_merge(
       static::getMailPoetPages(),
       WPFunctions::get()->getPages()
@@ -79,7 +79,7 @@ class Pages {
     return $pages;
   }
 
-  static function getPageData($page) {
+  public static function getPageData($page) {
     $subscription_url_factory = Subscription\SubscriptionUrlFactory::getInstance();
     return [
       'id' => $page->ID,
diff --git a/lib/Settings/SettingsController.php b/lib/Settings/SettingsController.php
index 7baf8604e4..1e711bd8f9 100644
--- a/lib/Settings/SettingsController.php
+++ b/lib/Settings/SettingsController.php
@@ -24,11 +24,11 @@ class SettingsController {
   /** @var SettingsRepository */
   private $settings_repository;
 
-  function __construct(SettingsRepository $settings_repository) {
+  public function __construct(SettingsRepository $settings_repository) {
     $this->settings_repository = $settings_repository;
   }
 
-  function get($key, $default = null) {
+  public function get($key, $default = null) {
     $this->ensureLoaded();
     $key_parts = explode('.', $key);
     $setting = $this->settings;
@@ -48,7 +48,7 @@ class SettingsController {
     return $setting;
   }
 
-  function getAllDefaults() {
+  public function getAllDefaults() {
     if ($this->defaults === null) {
       $this->defaults = [
         'mta_group' => self::DEFAULT_SENDING_METHOD_GROUP,
@@ -84,19 +84,19 @@ class SettingsController {
    * Fetches the value from DB and update in cache
    * This is required for sync settings between parallel processes e.g. cron
    */
-  function fetch($key, $default = null) {
+  public function fetch($key, $default = null) {
     $keys = explode('.', $key);
     $main_key = $keys[0];
     $this->settings[$main_key] = $this->fetchValue($main_key);
     return $this->get($key, $default);
   }
 
-  function getAll() {
+  public function getAll() {
     $this->ensureLoaded();
     return array_replace_recursive($this->getAllDefaults(), $this->settings);
   }
 
-  function set($key, $value) {
+  public function set($key, $value) {
     $this->ensureLoaded();
     $key_parts = explode('.', $key);
     $main_key = $key_parts[0];
@@ -112,7 +112,7 @@ class SettingsController {
     $this->settings_repository->createOrUpdateByName($main_key, $this->settings[$main_key]);
   }
 
-  function delete($key) {
+  public function delete($key) {
     $setting = $this->settings_repository->findOneByName($key);
     if ($setting) {
       $this->settings_repository->remove($setting);
@@ -150,13 +150,13 @@ class SettingsController {
     return $setting ? $setting->getValue() : null;
   }
 
-  function resetCache() {
+  public function resetCache() {
     $this->settings = [];
     $this->loaded = false;
   }
 
   /** @return SettingsController */
-  static function getInstance() {
+  public static function getInstance() {
     return ContainerWrapper::getInstance()->get(SettingsController::class);
   }
 }
diff --git a/lib/Settings/SettingsRepository.php b/lib/Settings/SettingsRepository.php
index a8abad9ae9..e53f9a99cb 100644
--- a/lib/Settings/SettingsRepository.php
+++ b/lib/Settings/SettingsRepository.php
@@ -16,11 +16,11 @@ use MailPoetVendor\Carbon\Carbon;
  * @method void remove(SettingEntity $entity)
  */
 class SettingsRepository extends Repository {
-  function findOneByName($name) {
+  public function findOneByName($name) {
     return $this->doctrine_repository->findOneBy(['name' => $name]);
   }
 
-  function createOrUpdateByName($name, $value) {
+  public function createOrUpdateByName($name, $value) {
     // Temporarily use low-level INSERT ... ON DUPLICATE KEY UPDATE query to avoid race conditions
     // between entity fetch and creation with multiple concurrent requests. This will be replaced
     // by a code solving atomicity of create-or-update on entity (ORM) level in a follow-up ticket.
@@ -29,7 +29,7 @@ class SettingsRepository extends Repository {
     $this->entity_manager->getConnection()->executeUpdate("
       INSERT INTO $table_name (name, value, created_at, updated_at)
       VALUES (:name, :value, :now, :now)
-      ON DUPLICATE KEY UPDATE value = :value, updated_at = :now 
+      ON DUPLICATE KEY UPDATE value = :value, updated_at = :now
     ", [
       'name' => $name,
       'value' => is_array($value) ? serialize($value) : $value,
diff --git a/lib/Settings/UserFlagsController.php b/lib/Settings/UserFlagsController.php
index 3ee5e66f00..f495510d01 100644
--- a/lib/Settings/UserFlagsController.php
+++ b/lib/Settings/UserFlagsController.php
@@ -16,7 +16,7 @@ class UserFlagsController {
   /** @var UserFlagsRepository */
   private $user_flags_repository;
 
-  function __construct(UserFlagsRepository $user_flags_repository) {
+  public function __construct(UserFlagsRepository $user_flags_repository) {
     $this->defaults = [
       'last_announcement_seen' => false,
       'editor_tutorial_seen' => false,
@@ -24,7 +24,7 @@ class UserFlagsController {
     $this->user_flags_repository = $user_flags_repository;
   }
 
-  function get($name) {
+  public function get($name) {
     $this->ensureLoaded();
     if (!isset($this->data[$name])) {
       return $this->defaults[$name];
@@ -32,7 +32,7 @@ class UserFlagsController {
     return $this->data[$name];
   }
 
-  function getAll() {
+  public function getAll() {
     $this->ensureLoaded();
     $data = $this->data;
     if (!is_array($data)) {
@@ -41,7 +41,7 @@ class UserFlagsController {
     return array_merge($this->defaults, $data);
   }
 
-  function set($name, $value) {
+  public function set($name, $value) {
     $current_user_id = WPFunctions::get()->getCurrentUserId();
     $flag = $this->user_flags_repository->findOneBy([
       'user_id' => $current_user_id,
@@ -62,7 +62,7 @@ class UserFlagsController {
     }
   }
 
-  function delete($name) {
+  public function delete($name) {
     $current_user_id = WPFunctions::get()->getCurrentUserId();
     $flag = $this->user_flags_repository->findOneBy([
       'user_id' => $current_user_id,
diff --git a/lib/Statistics/GATracking.php b/lib/Statistics/GATracking.php
index ee5c629545..162904df97 100644
--- a/lib/Statistics/GATracking.php
+++ b/lib/Statistics/GATracking.php
@@ -13,11 +13,11 @@ class GATracking {
   /** @var SecondLevelDomainNames */
   private $secondLevelDomainNames;
 
-  function __construct() {
+  public function __construct() {
     $this->secondLevelDomainNames = new SecondLevelDomainNames();
   }
 
-  function applyGATracking($rendered_newsletter, $newsletter, $internal_host = null) {
+  public function applyGATracking($rendered_newsletter, $newsletter, $internal_host = null) {
     if ($newsletter instanceof Newsletter && $newsletter->type == Newsletter::TYPE_NOTIFICATION_HISTORY) {
       $parent_newsletter = $newsletter->parent()->findOne();
       $field = $parent_newsletter->ga_campaign;
diff --git a/lib/Statistics/Track/Clicks.php b/lib/Statistics/Track/Clicks.php
index 6802e8de6b..c50ce76162 100644
--- a/lib/Statistics/Track/Clicks.php
+++ b/lib/Statistics/Track/Clicks.php
@@ -31,7 +31,7 @@ class Clicks {
   /**
    * @param \stdClass|null $data
    */
-  function track($data) {
+  public function track($data) {
     if (!$data || empty($data->link)) {
       return $this->abort();
     }
@@ -90,7 +90,7 @@ class Clicks {
     }
   }
 
-  function processUrl($url, $newsletter, $subscriber, $queue, $wp_user_preview) {
+  public function processUrl($url, $newsletter, $subscriber, $queue, $wp_user_preview) {
     if (preg_match('/\[link:(?P<action>.*?)\]/', $url, $shortcode)) {
       if (!$shortcode['action']) $this->abort();
       $url = Link::processShortcodeAction(
@@ -107,13 +107,13 @@ class Clicks {
     return $url;
   }
 
-  function abort() {
+  public function abort() {
     WPFunctions::get()->statusHeader(404);
     WPFunctions::get()->getTemplatePart((string)404);
     exit;
   }
 
-  function redirectToUrl($url) {
+  public function redirectToUrl($url) {
     header('Location: ' . $url, true, 302);
     exit;
   }
diff --git a/lib/Statistics/Track/Opens.php b/lib/Statistics/Track/Opens.php
index 37bfeabc95..1d14ba9ff1 100644
--- a/lib/Statistics/Track/Opens.php
+++ b/lib/Statistics/Track/Opens.php
@@ -5,7 +5,7 @@ namespace MailPoet\Statistics\Track;
 use MailPoet\Models\StatisticsOpens;
 
 class Opens {
-  function track($data, $display_image = true) {
+  public function track($data, $display_image = true) {
     if (!$data) {
       return $this->returnResponse($display_image);
     }
@@ -25,7 +25,7 @@ class Opens {
     return $this->returnResponse($display_image);
   }
 
-  function returnResponse($display_image) {
+  public function returnResponse($display_image) {
     if (!$display_image) return;
     // return 1x1 pixel transparent gif image
     header('Content-Type: image/gif');
diff --git a/lib/Statistics/Track/Unsubscribes.php b/lib/Statistics/Track/Unsubscribes.php
index ade6a704cb..d009c6c19e 100644
--- a/lib/Statistics/Track/Unsubscribes.php
+++ b/lib/Statistics/Track/Unsubscribes.php
@@ -5,7 +5,7 @@ namespace MailPoet\Statistics\Track;
 use MailPoet\Models\StatisticsUnsubscribes;
 
 class Unsubscribes {
-  function track($newsletter_id, $subscriber_id, $queue_id) {
+  public function track($newsletter_id, $subscriber_id, $queue_id) {
     $statistics = StatisticsUnsubscribes::where('subscriber_id', $subscriber_id)
       ->where('newsletter_id', $newsletter_id)
       ->where('queue_id', $queue_id)
diff --git a/lib/Statistics/Track/WooCommercePurchases.php b/lib/Statistics/Track/WooCommercePurchases.php
index e148bf1d0d..cf8baf0b23 100644
--- a/lib/Statistics/Track/WooCommercePurchases.php
+++ b/lib/Statistics/Track/WooCommercePurchases.php
@@ -18,12 +18,12 @@ class WooCommercePurchases {
   /** @var Cookies */
   private $cookies;
 
-  function __construct(Helper $woocommerce_helper, Cookies $cookies) {
+  public function __construct(Helper $woocommerce_helper, Cookies $cookies) {
     $this->woocommerce_helper = $woocommerce_helper;
     $this->cookies = $cookies;
   }
 
-  function trackPurchase($id, $use_cookies = true) {
+  public function trackPurchase($id, $use_cookies = true) {
     $order = $this->woocommerce_helper->wcGetOrder($id);
     if (!$order instanceof WC_Order) {
       return;
diff --git a/lib/Subscribers/ConfirmationEmailMailer.php b/lib/Subscribers/ConfirmationEmailMailer.php
index 26f5494140..69ebb243ce 100644
--- a/lib/Subscribers/ConfirmationEmailMailer.php
+++ b/lib/Subscribers/ConfirmationEmailMailer.php
@@ -32,7 +32,7 @@ class ConfirmationEmailMailer {
   /** @var SubscriptionUrlFactory */
   private $subscription_url_factory;
 
-  function __construct(Mailer $mailer, WPFunctions $wp, SettingsController $settings, SubscriptionUrlFactory $subscription_url_factory) {
+  public function __construct(Mailer $mailer, WPFunctions $wp, SettingsController $settings, SubscriptionUrlFactory $subscription_url_factory) {
     $this->mailer = $mailer;
     $this->wp = $wp;
     $this->settings = $settings;
@@ -40,7 +40,7 @@ class ConfirmationEmailMailer {
     $this->subscription_url_factory = $subscription_url_factory;
   }
 
-  function sendConfirmationEmail(Subscriber $subscriber) {
+  public function sendConfirmationEmail(Subscriber $subscriber) {
     $signup_confirmation = $this->settings->get('signup_confirmation');
     if ((bool)$signup_confirmation['enabled'] === false) {
       return false;
diff --git a/lib/Subscribers/ImportExport/Export/DynamicSubscribersGetter.php b/lib/Subscribers/ImportExport/Export/DynamicSubscribersGetter.php
index e0325e0537..d8bdde4b6e 100644
--- a/lib/Subscribers/ImportExport/Export/DynamicSubscribersGetter.php
+++ b/lib/Subscribers/ImportExport/Export/DynamicSubscribersGetter.php
@@ -16,7 +16,7 @@ class DynamicSubscribersGetter extends SubscribersGetter {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct($segments_ids, $batch_size, WPFunctions $wp = null) {
+  public function __construct($segments_ids, $batch_size, WPFunctions $wp = null) {
     parent::__construct($segments_ids, $batch_size);
     if ($wp == null) {
       $wp = new WPFunctions;
diff --git a/lib/Subscribers/ImportExport/Export/Export.php b/lib/Subscribers/ImportExport/Export/Export.php
index 4c251633e8..0393a2b5e6 100644
--- a/lib/Subscribers/ImportExport/Export/Export.php
+++ b/lib/Subscribers/ImportExport/Export/Export.php
@@ -51,15 +51,15 @@ class Export {
     $this->export_file_URL = $this->getExportFileURL($this->export_file);
   }
 
-  static function getFilePrefix() {
+  public static function getFilePrefix() {
     return 'MailPoet_export_';
   }
 
-  static function getExportPath() {
+  public static function getExportPath() {
     return Env::$temp_path;
   }
 
-  function process() {
+  public function process() {
     $processed_subscribers = 0;
     $this->default_subscribers_getter->reset();
     try {
@@ -85,7 +85,7 @@ class Export {
     ];
   }
 
-  function generateCSV() {
+  public function generateCSV() {
     $processed_subscribers = 0;
     $formatted_subscriber_fields = $this->formatted_subscriber_fields;
     $CSV_file = fopen($this->export_file, 'w');
@@ -121,7 +121,7 @@ class Export {
     return $processed_subscribers;
   }
 
-  function generateXLSX() {
+  public function generateXLSX() {
     $processed_subscribers = 0;
     $XLSX_writer = new XLSXWriter();
     $XLSX_writer->setAuthor('MailPoet (www.mailpoet.com)');
@@ -172,11 +172,11 @@ class Export {
     return $processed_subscribers;
   }
 
-  function writeXLSX($XLSX_writer, $segment, $data) {
+  public function writeXLSX($XLSX_writer, $segment, $data) {
     return $XLSX_writer->writeSheetRow(ucwords($segment), $data);
   }
 
-  function getSubscribers() {
+  public function getSubscribers() {
     $subscribers = $this->default_subscribers_getter->get();
     if ($subscribers === false) {
       $subscribers = $this->dynamic_subscribers_getter->get();
@@ -184,7 +184,7 @@ class Export {
     return $subscribers;
   }
 
-  function getExportFileURL($file) {
+  public function getExportFileURL($file) {
     return sprintf(
       '%s/%s',
       Env::$temp_url,
@@ -192,7 +192,7 @@ class Export {
     );
   }
 
-  function getExportFile($format) {
+  public function getExportFile($format) {
     return sprintf(
       $this->export_path . '/' . self::getFilePrefix() . '%s.%s',
       Security::generateRandomString(15),
@@ -200,7 +200,7 @@ class Export {
     );
   }
 
-  function getSubscriberCustomFields() {
+  public function getSubscriberCustomFields() {
     return array_column(
       CustomField::findArray(),
       'name',
@@ -208,7 +208,7 @@ class Export {
     );
   }
 
-  function formatSubscriberFields($subscriber_fields, $subscriber_custom_fields) {
+  public function formatSubscriberFields($subscriber_fields, $subscriber_custom_fields) {
     $export_factory = new ImportExportFactory('export');
     $translated_fields = $export_factory->getSubscriberFields();
     return array_map(function($field) use (
@@ -222,7 +222,7 @@ class Export {
     }, $subscriber_fields);
   }
 
-  function formatSubscriberData($subscriber) {
+  public function formatSubscriberData($subscriber) {
     return array_map(function($field) use ($subscriber) {
       return $subscriber[$field];
     }, $this->subscriber_fields);
diff --git a/lib/Subscribers/ImportExport/Import/Import.php b/lib/Subscribers/ImportExport/Import/Import.php
index 697fc92b3b..2e6f827dab 100644
--- a/lib/Subscribers/ImportExport/Import/Import.php
+++ b/lib/Subscribers/ImportExport/Import/Import.php
@@ -53,7 +53,7 @@ class Import {
     ];
   }
 
-  function validateImportData($data) {
+  public function validateImportData($data) {
     $required_data_fields = [
       'subscribers',
       'columns',
@@ -70,7 +70,7 @@ class Import {
     }
   }
 
-  function process() {
+  public function process() {
     // validate data based on field validation rules
     $subscribers_data = $this->validateSubscribersData($this->subscribers_data);
     if (!$subscribers_data) {
@@ -136,7 +136,7 @@ class Import {
     ];
   }
 
-  function validateSubscribersData($subscribers_data) {
+  public function validateSubscribersData($subscribers_data) {
     $invalid_records = [];
     $validator = new ModelValidator();
     foreach ($subscribers_data as $column => &$data) {
@@ -182,7 +182,7 @@ class Import {
     return $subscribers_data;
   }
 
-  function transformSubscribersData($subscribers, $columns) {
+  public function transformSubscribersData($subscribers, $columns) {
     $transformed_subscribers = [];
     foreach ($columns as $column => $data) {
       $transformed_subscribers[$column] = array_column($subscribers, $data['index']);
@@ -190,7 +190,7 @@ class Import {
     return $transformed_subscribers;
   }
 
-  function splitSubscribersData($subscribers_data) {
+  public function splitSubscribersData($subscribers_data) {
     // $subscribers_data is an two-dimensional associative array
     // of all subscribers being imported: [field => [value1, value2], field => [value1, value2], ...]
     $temp_existing_subscribers = [];
@@ -238,7 +238,7 @@ class Import {
     ];
   }
 
-  function deleteExistingTrashedSubscribers($subscribers_data) {
+  public function deleteExistingTrashedSubscribers($subscribers_data) {
     $existing_trashed_records = array_filter(
       array_map(function($subscriber_emails) {
         return Subscriber::selectMany(['id'])
@@ -257,7 +257,7 @@ class Import {
     }
   }
 
-  function addMissingRequiredFields($subscribers) {
+  public function addMissingRequiredFields($subscribers) {
     $subscribers_count = count($subscribers['data'][key($subscribers['data'])]);
     foreach (array_keys($this->required_subscribers_fields) as $required_field) {
       if (in_array($required_field, $subscribers['fields'])) continue;
@@ -308,7 +308,7 @@ class Import {
     return $subscribers_data;
   }
 
-  function getSubscribersFields($subscribers_fields) {
+  public function getSubscribersFields($subscribers_fields) {
     return array_values(
       array_filter(
         array_map(function($field) {
@@ -318,7 +318,7 @@ class Import {
     );
   }
 
-  function getCustomSubscribersFields($subscribers_fields) {
+  public function getCustomSubscribersFields($subscribers_fields) {
     return array_values(
       array_filter(
         array_map(function($field) {
@@ -328,7 +328,7 @@ class Import {
     );
   }
 
-  function createOrUpdateSubscribers(
+  public function createOrUpdateSubscribers(
     $action,
     $subscribers_data,
     $subscribers_custom_fields = false
@@ -378,7 +378,7 @@ class Import {
     return $created_or_updated_subscribers;
   }
 
-  function createOrUpdateCustomFields(
+  public function createOrUpdateCustomFields(
     $action,
     $created_or_updated_subscribers,
     $subscribers_data,
@@ -418,11 +418,11 @@ class Import {
     }
   }
 
-  function synchronizeWPUsers($wp_users) {
+  public function synchronizeWPUsers($wp_users) {
     return array_walk($wp_users, '\MailPoet\Segments\WP::synchronizeUser');
   }
 
-  function addSubscribersToSegments($subscribers_ids, $segments_ids) {
+  public function addSubscribersToSegments($subscribers_ids, $segments_ids) {
     foreach (array_chunk($subscribers_ids, self::DB_QUERY_CHUNK_SIZE) as $subscriber_ids_chunk) {
       SubscriberSegment::subscribeManyToSegments(
         $subscriber_ids_chunk, $segments_ids
diff --git a/lib/Subscribers/ImportExport/Import/MailChimp.php b/lib/Subscribers/ImportExport/Import/MailChimp.php
index f13d37989b..df34ede106 100644
--- a/lib/Subscribers/ImportExport/Import/MailChimp.php
+++ b/lib/Subscribers/ImportExport/Import/MailChimp.php
@@ -13,7 +13,7 @@ class MailChimp {
   private $lists_url;
   const API_KEY_REGEX = '/[a-zA-Z0-9]{32}-[a-zA-Z0-9]{2,4}$/';
 
-  function __construct($api_key) {
+  public function __construct($api_key) {
     $this->api_key = $this->getAPIKey($api_key);
     $this->max_post_size = Helpers::getMaxPostSize('bytes');
     $this->data_center = $this->getDataCenter($this->api_key);
@@ -21,7 +21,7 @@ class MailChimp {
     $this->export_url = 'https://%s.api.mailchimp.com/export/1.0/list/?apikey=%s&id=%s';
   }
 
-  function getLists() {
+  public function getLists() {
     if (!$this->api_key || !$this->data_center) {
       return $this->throwException('API');
     }
@@ -59,7 +59,7 @@ class MailChimp {
     return $lists;
   }
 
-  function getSubscribers($lists = []) {
+  public function getSubscribers($lists = []) {
     if (!$this->api_key || !$this->data_center) {
       return $this->throwException('API');
     }
@@ -122,17 +122,17 @@ class MailChimp {
     ];
   }
 
-  function getDataCenter($api_key) {
+  public function getDataCenter($api_key) {
     if (!$api_key) return false;
     $api_key_parts = explode('-', $api_key);
     return end($api_key_parts);
   }
 
-  function getAPIKey($api_key) {
+  public function getAPIKey($api_key) {
     return (preg_match(self::API_KEY_REGEX, $api_key)) ? $api_key : false;
   }
 
-  function throwException($error) {
+  public function throwException($error) {
     $errorMessage = WPFunctions::get()->__('Unknown MailChimp error.', 'mailpoet');
     switch ($error) {
       case 'API':
diff --git a/lib/Subscribers/ImportExport/ImportExportFactory.php b/lib/Subscribers/ImportExport/ImportExportFactory.php
index 114de79c66..18586a6996 100644
--- a/lib/Subscribers/ImportExport/ImportExportFactory.php
+++ b/lib/Subscribers/ImportExport/ImportExportFactory.php
@@ -15,12 +15,12 @@ class ImportExportFactory {
 
   private $wp;
 
-  function __construct($action = null) {
+  public function __construct($action = null) {
     $this->action = $action;
     $this->wp = new WPFunctions;
   }
 
-  function getSegments() {
+  public function getSegments() {
     if ($this->action === self::IMPORT_ACTION) {
       $segments = Segment::getSegmentsForImport();
     } else {
@@ -42,7 +42,7 @@ class ImportExportFactory {
     }, $segments);
   }
 
-  function getSubscriberFields() {
+  public function getSubscriberFields() {
     $fields = [
       'email' => WPFunctions::get()->__('Email', 'mailpoet'),
       'first_name' => WPFunctions::get()->__('First name', 'mailpoet'),
@@ -61,7 +61,7 @@ class ImportExportFactory {
     return $fields;
   }
 
-  function formatSubscriberFields($subscriber_fields) {
+  public function formatSubscriberFields($subscriber_fields) {
     return array_map(function($field_id, $field_name) {
       return [
         'id' => $field_id,
@@ -72,11 +72,11 @@ class ImportExportFactory {
     }, array_keys($subscriber_fields), $subscriber_fields);
   }
 
-  function getSubscriberCustomFields() {
+  public function getSubscriberCustomFields() {
     return CustomField::findArray();
   }
 
-  function formatSubscriberCustomFields($subscriber_custom_fields) {
+  public function formatSubscriberCustomFields($subscriber_custom_fields) {
     return array_map(function($field) {
       return [
         'id' => $field['id'],
@@ -88,7 +88,7 @@ class ImportExportFactory {
     }, $subscriber_custom_fields);
   }
 
-  function formatFieldsForSelect2(
+  public function formatFieldsForSelect2(
     $subscriber_fields,
     $subscriber_custom_fields) {
     $actions = ($this->action === 'import') ?
@@ -133,7 +133,7 @@ class ImportExportFactory {
     return $select2Fields;
   }
 
-  function bootstrap() {
+  public function bootstrap() {
     $subscriber_fields = $this->getSubscriberFields();
     $subscriber_custom_fields = $this->getSubscriberCustomFields();
     $data['segments'] = json_encode($this->getSegments());
diff --git a/lib/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporter.php b/lib/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporter.php
index 4dd58dd7ab..203b0837ba 100644
--- a/lib/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporter.php
+++ b/lib/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporter.php
@@ -10,7 +10,7 @@ class NewsletterClicksExporter {
 
   const LIMIT = 100;
 
-  function export($email, $page = 1) {
+  public function export($email, $page = 1) {
     $data = $this->exportSubscriber(Subscriber::findOne(trim($email)), $page);
     return [
       'data' => $data,
diff --git a/lib/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporter.php b/lib/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporter.php
index 6de0798040..c5fe8f56e9 100644
--- a/lib/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporter.php
+++ b/lib/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporter.php
@@ -12,7 +12,7 @@ class NewslettersExporter {
 
   const LIMIT = 100;
 
-  function export($email, $page = 1) {
+  public function export($email, $page = 1) {
     $data = $this->exportSubscriber(Subscriber::findOne(trim($email)), $page);
     return [
       'data' => $data,
diff --git a/lib/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporter.php b/lib/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporter.php
index 4dfcc70499..b5f337da30 100644
--- a/lib/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporter.php
+++ b/lib/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporter.php
@@ -7,7 +7,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class SegmentsExporter {
 
-  function export($email) {
+  public function export($email) {
     return [
       'data' => $this->exportSubscriber(Subscriber::findOne(trim($email))),
       'done' => true,
diff --git a/lib/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporter.php b/lib/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporter.php
index 2125a926fa..b0172563cb 100644
--- a/lib/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporter.php
+++ b/lib/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporter.php
@@ -9,7 +9,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class SubscriberExporter {
 
-  function export($email) {
+  public function export($email) {
     return [
       'data' => $this->exportSubscriber(Subscriber::findOne(trim($email))),
       'done' => true,
diff --git a/lib/Subscribers/InactiveSubscribersController.php b/lib/Subscribers/InactiveSubscribersController.php
index f20af8db03..470f26e05b 100644
--- a/lib/Subscribers/InactiveSubscribersController.php
+++ b/lib/Subscribers/InactiveSubscribersController.php
@@ -19,7 +19,7 @@ class InactiveSubscribersController {
   /** @var SettingsRepository */
   private $settings_repository;
 
-  function __construct(SettingsRepository $settings_repository) {
+  public function __construct(SettingsRepository $settings_repository) {
     $this->settings_repository = $settings_repository;
   }
 
@@ -28,7 +28,7 @@ class InactiveSubscribersController {
    * @param int $batch_size
    * @return int|boolean
    */
-  function markInactiveSubscribers($days_to_inactive, $batch_size, $start_id = null) {
+  public function markInactiveSubscribers($days_to_inactive, $batch_size, $start_id = null) {
     $threshold_date = $this->getThresholdDate($days_to_inactive);
     return $this->deactivateSubscribers($threshold_date, $batch_size, $start_id);
   }
@@ -38,7 +38,7 @@ class InactiveSubscribersController {
    * @param int $batch_size
    * @return int
    */
-  function markActiveSubscribers($days_to_inactive, $batch_size) {
+  public function markActiveSubscribers($days_to_inactive, $batch_size) {
     $threshold_date = $this->getThresholdDate($days_to_inactive);
     return $this->activateSubscribers($threshold_date, $batch_size);
   }
@@ -46,7 +46,7 @@ class InactiveSubscribersController {
   /**
    * @return void
    */
-  function reactivateInactiveSubscribers() {
+  public function reactivateInactiveSubscribers() {
     $reactivate_all_inactive_query = sprintf(
       "UPDATE %s SET status = '%s' WHERE status = '%s';",
       Subscriber::$_table, Subscriber::STATUS_SUBSCRIBED, Subscriber::STATUS_INACTIVE
diff --git a/lib/Subscribers/LinkTokens.php b/lib/Subscribers/LinkTokens.php
index b8a90b77c4..ab1fdd5ed9 100644
--- a/lib/Subscribers/LinkTokens.php
+++ b/lib/Subscribers/LinkTokens.php
@@ -9,7 +9,7 @@ class LinkTokens {
   const OBSOLETE_LINK_TOKEN_LENGTH = 6;
   const LINK_TOKEN_LENGTH = 32;
 
-  function getToken(Subscriber $subscriber) {
+  public function getToken(Subscriber $subscriber) {
     if ($subscriber->link_token === null) {
       $subscriber->link_token = $this->generateToken($subscriber->email);
       // `$subscriber->save()` fails if the subscriber has subscriptions, segments or custom fields
@@ -18,7 +18,7 @@ class LinkTokens {
     return $subscriber->link_token;
   }
 
-  function verifyToken(Subscriber $subscriber, $token) {
+  public function verifyToken(Subscriber $subscriber, $token) {
     $database_token = $this->getToken($subscriber);
     $request_token = substr($token, 0, strlen($database_token));
     return call_user_func(
diff --git a/lib/Subscribers/NewSubscriberNotificationMailer.php b/lib/Subscribers/NewSubscriberNotificationMailer.php
index a05e00d20c..984bfdb1a0 100644
--- a/lib/Subscribers/NewSubscriberNotificationMailer.php
+++ b/lib/Subscribers/NewSubscriberNotificationMailer.php
@@ -26,7 +26,7 @@ class NewSubscriberNotificationMailer {
   /** @var MetaInfo */
   private $mailerMetaInfo;
 
-  function __construct(Mailer $mailer, Renderer $renderer, SettingsController $settings) {
+  public function __construct(Mailer $mailer, Renderer $renderer, SettingsController $settings) {
     $this->mailer = $mailer;
     $this->renderer = $renderer;
     $this->settings = $settings;
@@ -39,7 +39,7 @@ class NewSubscriberNotificationMailer {
    *
    * @throws \Exception
    */
-  function send(Subscriber $subscriber, array $segments) {
+  public function send(Subscriber $subscriber, array $segments) {
     $settings = $this->settings->get(NewSubscriberNotificationMailer::SETTINGS_KEY);
     if ($this->isDisabled($settings)) {
       return;
diff --git a/lib/Subscribers/Source.php b/lib/Subscribers/Source.php
index d31e9ddb78..db2e8e26de 100644
--- a/lib/Subscribers/Source.php
+++ b/lib/Subscribers/Source.php
@@ -26,7 +26,7 @@ class Source {
     Source::UNKNOWN,
   ];
 
-  static function setSource(Subscriber $subscriber, $source) {
+  public static function setSource(Subscriber $subscriber, $source) {
     if ((isset($subscriber->source)) && ($subscriber->source !== Source::UNKNOWN)) {
       // we don't want to override source
       return $subscriber;
diff --git a/lib/Subscribers/SubscriberActions.php b/lib/Subscribers/SubscriberActions.php
index 190cd6b9ad..44f6162564 100644
--- a/lib/Subscribers/SubscriberActions.php
+++ b/lib/Subscribers/SubscriberActions.php
@@ -36,7 +36,7 @@ class SubscriberActions {
     $this->welcome_scheduler = $welcome_scheduler;
   }
 
-  function subscribe($subscriber_data = [], $segment_ids = []) {
+  public function subscribe($subscriber_data = [], $segment_ids = []) {
     // filter out keys from the subscriber_data array
     // that should not be editable when subscribing
     $subscriber_data = Subscriber::filterOutReservedColumns($subscriber_data);
diff --git a/lib/Subscribers/SubscriberPersonalDataEraser.php b/lib/Subscribers/SubscriberPersonalDataEraser.php
index bdbe9d3e76..2ef4809ef3 100644
--- a/lib/Subscribers/SubscriberPersonalDataEraser.php
+++ b/lib/Subscribers/SubscriberPersonalDataEraser.php
@@ -7,7 +7,7 @@ use MailPoet\Models\SubscriberCustomField;
 
 class SubscriberPersonalDataEraser {
 
-  function erase($email) {
+  public function erase($email) {
     if (empty($email)) {
       return [
         'items_removed' => false,
diff --git a/lib/Subscription/Captcha.php b/lib/Subscription/Captcha.php
index 3f60ef1c8f..31ecb44576 100644
--- a/lib/Subscription/Captcha.php
+++ b/lib/Subscription/Captcha.php
@@ -19,7 +19,7 @@ class Captcha {
   /** @var CaptchaSession  */
   private $captcha_session;
 
-  function __construct(WPFunctions $wp = null, CaptchaSession $captcha_session = null) {
+  public function __construct(WPFunctions $wp = null, CaptchaSession $captcha_session = null) {
     if ($wp === null) {
       $wp = new WPFunctions;
     }
@@ -30,11 +30,11 @@ class Captcha {
     $this->captcha_session = $captcha_session;
   }
 
-  function isSupported() {
+  public function isSupported() {
     return extension_loaded('gd') && function_exists('imagettftext');
   }
 
-  function isRequired($subscriber_email = null) {
+  public function isRequired($subscriber_email = null) {
     if ($this->isUserExemptFromCaptcha()) {
       return false;
     }
@@ -81,7 +81,7 @@ class Captcha {
     return !empty(array_intersect($roles, (array)$user->roles));
   }
 
-  function renderImage($width = null, $height = null, $session_id = null, $return = false) {
+  public function renderImage($width = null, $height = null, $session_id = null, $return = false) {
     if (!$this->isSupported()) {
       return false;
     }
diff --git a/lib/Subscription/CaptchaRenderer.php b/lib/Subscription/CaptchaRenderer.php
index bcf232115c..cb318a376a 100644
--- a/lib/Subscription/CaptchaRenderer.php
+++ b/lib/Subscription/CaptchaRenderer.php
@@ -20,7 +20,7 @@ class CaptchaRenderer {
   /** @var SubscriptionUrlFactory */
   private $subscription_url_factory;
 
-  function __construct(UrlHelper $url_helper, WPFunctions $wp, CaptchaSession $captcha_session, SubscriptionUrlFactory $subscription_url_factory) {
+  public function __construct(UrlHelper $url_helper, WPFunctions $wp, CaptchaSession $captcha_session, SubscriptionUrlFactory $subscription_url_factory) {
     $this->url_helper = $url_helper;
     $this->wp = $wp;
     $this->captcha_session = $captcha_session;
diff --git a/lib/Subscription/CaptchaSession.php b/lib/Subscription/CaptchaSession.php
index 99bb442c12..23d818d565 100644
--- a/lib/Subscription/CaptchaSession.php
+++ b/lib/Subscription/CaptchaSession.php
@@ -18,39 +18,39 @@ class CaptchaSession {
   /** @var string */
   private $id;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function init($id = null) {
+  public function init($id = null) {
     $this->id = $id ?: Security::generateRandomString(self::ID_LENGTH);
   }
 
-  function getId() {
+  public function getId() {
     if ($this->id === null) {
       throw new \Exception("MailPoet captcha session not initialized.");
     }
     return $this->id;
   }
 
-  function reset() {
+  public function reset() {
     $this->wp->deleteTransient($this->getKey(self::SESSION_FORM_KEY));
     $this->wp->deleteTransient($this->getKey(self::SESSION_HASH_KEY));
   }
 
-  function setFormData(array $data) {
+  public function setFormData(array $data) {
     $this->wp->setTransient($this->getKey(self::SESSION_FORM_KEY), $data, self::EXPIRATION);
   }
 
-  function getFormData() {
+  public function getFormData() {
     return $this->wp->getTransient($this->getKey(self::SESSION_FORM_KEY));
   }
 
-  function setCaptchaHash($hash) {
+  public function setCaptchaHash($hash) {
     $this->wp->setTransient($this->getKey(self::SESSION_HASH_KEY), $hash, self::EXPIRATION);
   }
 
-  function getCaptchaHash() {
+  public function getCaptchaHash() {
     return $this->wp->getTransient($this->getKey(self::SESSION_HASH_KEY));
   }
 
diff --git a/lib/Subscription/Comment.php b/lib/Subscription/Comment.php
index 7949490ec7..44451a1773 100644
--- a/lib/Subscription/Comment.php
+++ b/lib/Subscription/Comment.php
@@ -17,7 +17,7 @@ class Comment {
   /** @var SubscriberActions */
   private $subscriber_actions;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     SubscriberActions $subscriber_actions
   ) {
@@ -25,12 +25,12 @@ class Comment {
     $this->subscriber_actions = $subscriber_actions;
   }
 
-  function extendLoggedInForm($field) {
+  public function extendLoggedInForm($field) {
     $field .= $this->getSubscriptionField();
     return $field;
   }
 
-  function extendLoggedOutForm() {
+  public function extendLoggedOutForm() {
     echo $this->getSubscriptionField();
   }
 
@@ -52,7 +52,7 @@ class Comment {
     </p>';
   }
 
-  function onSubmit($comment_id, $comment_status) {
+  public function onSubmit($comment_id, $comment_status) {
     if ($comment_status === Comment::SPAM) return;
 
     if (
@@ -74,7 +74,7 @@ class Comment {
     }
   }
 
-  function onStatusUpdate($comment_id, $action) {
+  public function onStatusUpdate($comment_id, $action) {
     if ($action === 'approve') {
       // check if the comment's author wants to subscribe
       $do_subscribe = (
diff --git a/lib/Subscription/Form.php b/lib/Subscription/Form.php
index 40b9dea65f..cf04494927 100644
--- a/lib/Subscription/Form.php
+++ b/lib/Subscription/Form.php
@@ -15,12 +15,12 @@ class Form {
   /** @var UrlHelper */
   private $url_helper;
 
-  function __construct(API $api, UrlHelper $url_helper) {
+  public function __construct(API $api, UrlHelper $url_helper) {
     $this->api = $api;
     $this->url_helper = $url_helper;
   }
 
-  function onSubmit($request_data = false) {
+  public function onSubmit($request_data = false) {
     $request_data = ($request_data) ? $request_data : $_REQUEST;
     $this->api->setRequestData($request_data, Endpoint::TYPE_POST);
     $form_id = (!empty($request_data['data']['form_id'])) ? (int)$request_data['data']['form_id'] : false;
diff --git a/lib/Subscription/Manage.php b/lib/Subscription/Manage.php
index 482d264600..6643b42e10 100644
--- a/lib/Subscription/Manage.php
+++ b/lib/Subscription/Manage.php
@@ -19,13 +19,13 @@ class Manage {
   /** @var LinkTokens */
   private $link_tokens;
 
-  function __construct(UrlHelper $url_helper, FieldNameObfuscator $field_name_obfuscator, LinkTokens $link_tokens) {
+  public function __construct(UrlHelper $url_helper, FieldNameObfuscator $field_name_obfuscator, LinkTokens $link_tokens) {
     $this->url_helper = $url_helper;
     $this->field_name_obfuscator = $field_name_obfuscator;
     $this->link_tokens = $link_tokens;
   }
 
-  function onSave() {
+  public function onSave() {
     $action = (isset($_POST['action']) ? $_POST['action'] : null);
     $token = (isset($_POST['token']) ? $_POST['token'] : null);
 
diff --git a/lib/Subscription/Pages.php b/lib/Subscription/Pages.php
index 170bbd898a..71ccd662a8 100644
--- a/lib/Subscription/Pages.php
+++ b/lib/Subscription/Pages.php
@@ -55,7 +55,7 @@ class Pages {
   /** @var AssetsController */
   private $assets_controller;
 
-  function __construct(
+  public function __construct(
     NewSubscriberNotificationMailer $new_subscriber_notification_sender,
     WPFunctions $wp,
     SettingsController $settings,
@@ -77,7 +77,7 @@ class Pages {
     $this->assets_controller = $assets_controller;
   }
 
-  function init($action = false, $data = [], $init_shortcodes = false, $init_page_filters = false) {
+  public function init($action = false, $data = [], $init_shortcodes = false, $init_page_filters = false) {
     $this->action = $action;
     $this->data = $data;
     $this->subscriber = $this->getSubscriber();
@@ -90,14 +90,14 @@ class Pages {
     return (array_key_exists('preview', $_GET) || array_key_exists('preview', $this->data));
   }
 
-  function initPageFilters() {
+  public function initPageFilters() {
     $this->wp->addFilter('wp_title', [$this,'setWindowTitle'], 10, 3);
     $this->wp->addFilter('document_title_parts', [$this,'setWindowTitleParts'], 10, 1);
     $this->wp->addFilter('the_title', [$this,'setPageTitle'], 10, 1);
     $this->wp->addFilter('the_content', [$this,'setPageContent'], 10, 1);
   }
 
-  function initShortcodes() {
+  public function initShortcodes() {
     $this->wp->addShortcode('mailpoet_manage', [$this, 'getManageLink']);
     $this->wp->addShortcode('mailpoet_manage_subscription', [$this, 'getManageContent']);
   }
@@ -123,7 +123,7 @@ class Pages {
     return ($subscriber && $this->link_tokens->verifyToken($subscriber, $token)) ? $subscriber : false;
   }
 
-  function confirm() {
+  public function confirm() {
     $this->subscriber = $this->getSubscriber();
     if ($this->subscriber === false || $this->subscriber->status === Subscriber::STATUS_SUBSCRIBED) {
       return false;
@@ -158,7 +158,7 @@ class Pages {
     }
   }
 
-  function unsubscribe() {
+  public function unsubscribe() {
     if (!$this->isPreview()
       && ($this->subscriber !== false)
       && ($this->subscriber->status !== Subscriber::STATUS_UNSUBSCRIBED)
@@ -169,7 +169,7 @@ class Pages {
     }
   }
 
-  function setPageTitle($page_title = '') {
+  public function setPageTitle($page_title = '') {
     global $post;
 
     if ($this->action !== self::ACTION_CAPTCHA && $this->isPreview() === false && $this->subscriber === false) {
@@ -201,7 +201,7 @@ class Pages {
     }
   }
 
-  function setPageContent($page_content = '[mailpoet_page]') {
+  public function setPageContent($page_content = '[mailpoet_page]') {
     // if we're not in preview mode or captcha page and the subscriber does not exist
     if ($this->action !== self::ACTION_CAPTCHA && $this->isPreview() === false && $this->subscriber === false) {
       return $this->wp->__("Your email address doesn't appear in our lists anymore. Sign up again or contact us if this appears to be a mistake.", 'mailpoet');
@@ -234,7 +234,7 @@ class Pages {
     }
   }
 
-  function setWindowTitle($title, $separator, $separator_location = 'right') {
+  public function setWindowTitle($title, $separator, $separator_location = 'right') {
     $title_parts = explode(" $separator ", $title);
     if ($separator_location === 'right') {
       // first part
@@ -247,7 +247,7 @@ class Pages {
     return implode(" $separator ", $title_parts);
   }
 
-  function setWindowTitleParts($meta = []) {
+  public function setWindowTitleParts($meta = []) {
     $meta['title'] = $this->setPageTitle($meta['title']);
     return $meta;
   }
@@ -501,7 +501,7 @@ class Pages {
     return $content;
   }
 
-  function getManageLink($params) {
+  public function getManageLink($params) {
     if (!$this->subscriber) return $this->wp->__('Link to subscription management page is only available to mailing lists subscribers.', 'mailpoet');
 
     // get label or display default label
diff --git a/lib/Subscription/Registration.php b/lib/Subscription/Registration.php
index 8ff778eff1..8b69e07cbc 100644
--- a/lib/Subscription/Registration.php
+++ b/lib/Subscription/Registration.php
@@ -14,7 +14,7 @@ class Registration {
   /** @var SubscriberActions */
   private $subscriber_actions;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     SubscriberActions $subscriber_actions
   ) {
@@ -22,7 +22,7 @@ class Registration {
     $this->subscriber_actions = $subscriber_actions;
   }
 
-  function extendForm() {
+  public function extendForm() {
     $label = $this->settings->get(
       'subscribe.on_register.label',
       WPFunctions::get()->__('Yes, please add me to your mailing list.', 'mailpoet')
@@ -40,7 +40,7 @@ class Registration {
     </p>';
   }
 
-  function onMultiSiteRegister($result) {
+  public function onMultiSiteRegister($result) {
     if (empty($result['errors']->errors)) {
       if (
         isset($_POST['mailpoet']['subscribe_on_register'])
@@ -55,7 +55,7 @@ class Registration {
     return $result;
   }
 
-  function onRegister(
+  public function onRegister(
     $errors,
     $user_login,
     $user_email = null
diff --git a/lib/Subscription/SubscriptionUrlFactory.php b/lib/Subscription/SubscriptionUrlFactory.php
index 4d2e0a8ec2..c993e76e1f 100644
--- a/lib/Subscription/SubscriptionUrlFactory.php
+++ b/lib/Subscription/SubscriptionUrlFactory.php
@@ -30,12 +30,12 @@ class SubscriptionUrlFactory {
     $this->link_tokens = $link_tokens;
   }
 
-  function getCaptchaUrl($session_id) {
+  public function getCaptchaUrl($session_id) {
     $post = $this->getPost($this->settings->get('subscription.pages.captcha'));
     return $this->getSubscriptionUrl($post, 'captcha', null, ['captcha_session_id' => $session_id]);
   }
 
-  function getCaptchaImageUrl($width, $height, $session_id) {
+  public function getCaptchaImageUrl($width, $height, $session_id) {
     $post = $this->getPost($this->settings->get('subscription.pages.captcha'));
     return $this->getSubscriptionUrl(
       $post,
@@ -45,22 +45,22 @@ class SubscriptionUrlFactory {
     );
   }
 
-  function getConfirmationUrl(Subscriber $subscriber = null) {
+  public function getConfirmationUrl(Subscriber $subscriber = null) {
     $post = $this->getPost($this->settings->get('subscription.pages.confirmation'));
     return $this->getSubscriptionUrl($post, 'confirm', $subscriber);
   }
 
-  function getManageUrl(Subscriber $subscriber = null) {
+  public function getManageUrl(Subscriber $subscriber = null) {
     $post = $this->getPost($this->settings->get('subscription.pages.manage'));
     return $this->getSubscriptionUrl($post, 'manage', $subscriber);
   }
 
-  function getUnsubscribeUrl(Subscriber $subscriber = null) {
+  public function getUnsubscribeUrl(Subscriber $subscriber = null) {
     $post = $this->getPost($this->settings->get('subscription.pages.unsubscribe'));
     return $this->getSubscriptionUrl($post, 'unsubscribe', $subscriber);
   }
 
-  function getSubscriptionUrl(
+  public function getSubscriptionUrl(
     $post = null,
     $action = null,
     Subscriber $subscriber = null,
@@ -101,7 +101,7 @@ class SubscriptionUrlFactory {
   /**
    * @return SubscriptionUrlFactory
    */
-  static function getInstance() {
+  public static function getInstance() {
     if (!self::$instance instanceof SubscriptionUrlFactory) {
       self::$instance = new SubscriptionUrlFactory(new WPFunctions, SettingsController::getInstance(), new LinkTokens);
     }
diff --git a/lib/Subscription/Throttling.php b/lib/Subscription/Throttling.php
index 8f9d6675da..e302f15105 100644
--- a/lib/Subscription/Throttling.php
+++ b/lib/Subscription/Throttling.php
@@ -7,7 +7,7 @@ use MailPoet\Util\Helpers;
 use MailPoet\WP\Functions as WPFunctions;
 
 class Throttling {
-  static function throttle() {
+  public static function throttle() {
     $wp = new WPFunctions;
     $subscription_limit_enabled = $wp->applyFilters('mailpoet_subscription_limit_enabled', true);
 
@@ -48,7 +48,7 @@ class Throttling {
     return false;
   }
 
-  static function purge() {
+  public static function purge() {
     $wp = new WPFunctions;
     $interval = $wp->applyFilters('mailpoet_subscription_purge_window', MONTH_IN_SECONDS);
     return SubscriberIP::whereRaw(
@@ -57,7 +57,7 @@ class Throttling {
     )->deleteMany();
   }
 
-  static function secondsToTimeString($seconds) {
+  public static function secondsToTimeString($seconds) {
     $wp = new WPFunctions;
     $hrs = floor($seconds / 3600);
     $min = floor($seconds % 3600 / 60);
diff --git a/lib/Tasks/Bounce.php b/lib/Tasks/Bounce.php
index 1306cc7feb..8fb37e094e 100644
--- a/lib/Tasks/Bounce.php
+++ b/lib/Tasks/Bounce.php
@@ -7,7 +7,7 @@ use MailPoet\Models\ScheduledTaskSubscriber;
 use MailPoet\Models\Subscriber;
 
 class Bounce {
-  static function prepareSubscribers(ScheduledTask $task) {
+  public static function prepareSubscribers(ScheduledTask $task) {
     // Prepare subscribers on the DB side for performance reasons
     Subscriber::rawExecute(
       'INSERT IGNORE INTO ' . MP_SCHEDULED_TASK_SUBSCRIBERS_TABLE . '
diff --git a/lib/Tasks/Sending.php b/lib/Tasks/Sending.php
index 4bddb335a1..6627cd056d 100644
--- a/lib/Tasks/Sending.php
+++ b/lib/Tasks/Sending.php
@@ -70,11 +70,11 @@ class Sending {
     $this->task_subscribers = new Subscribers($task);
   }
 
-  static function create(ScheduledTask $task = null, SendingQueue $queue = null) {
+  public static function create(ScheduledTask $task = null, SendingQueue $queue = null) {
     return new self($task, $queue);
   }
 
-  static function createManyFromTasks($tasks) {
+  public static function createManyFromTasks($tasks) {
     if (empty($tasks)) {
       return [];
     }
@@ -98,7 +98,7 @@ class Sending {
     return $result;
   }
 
-  static function createFromQueue(SendingQueue $queue) {
+  public static function createFromQueue(SendingQueue $queue) {
     $task = $queue->task()->findOne();
     if (!$task) {
       return false;
@@ -107,7 +107,7 @@ class Sending {
     return self::create($task, $queue);
   }
 
-  static function getByNewsletterId($newsletter_id) {
+  public static function getByNewsletterId($newsletter_id) {
     $queue = SendingQueue::where('newsletter_id', $newsletter_id)
       ->orderByDesc('updated_at')
       ->findOne();
@@ -195,7 +195,7 @@ class Sending {
     return $this->updateCount()->getErrors() === false;
   }
 
-  function updateCount() {
+  public function updateCount() {
     $this->queue->count_processed = ScheduledTaskSubscriber::getProcessedCount($this->task->id);
     $this->queue->count_to_process = ScheduledTaskSubscriber::getUnprocessedCount($this->task->id);
     $this->queue->count_total = $this->queue->count_processed + $this->queue->count_to_process;
@@ -255,7 +255,7 @@ class Sending {
     return in_array($prop, $this->common_fields);
   }
 
-  static function getScheduledQueues($amount = self::RESULT_BATCH_SIZE) {
+  public static function getScheduledQueues($amount = self::RESULT_BATCH_SIZE) {
     $wp = new WPFunctions();
     $tasks = ScheduledTask::tableAlias('tasks')
       ->select('tasks.*')
@@ -270,7 +270,7 @@ class Sending {
     return static::createManyFromTasks($tasks);
   }
 
-  static function getRunningQueues($amount = self::RESULT_BATCH_SIZE) {
+  public static function getRunningQueues($amount = self::RESULT_BATCH_SIZE) {
     $tasks = ScheduledTask::orderByAsc('priority')
       ->orderByAsc('updated_at')
       ->whereNull('deleted_at')
diff --git a/lib/Tasks/State.php b/lib/Tasks/State.php
index 26bc9979c4..c015c3c9b7 100644
--- a/lib/Tasks/State.php
+++ b/lib/Tasks/State.php
@@ -14,7 +14,7 @@ class State
   /**
    * @return array
    */
-  function getCountsPerStatus() {
+  public function getCountsPerStatus() {
     $stats = [
       ScheduledTask::STATUS_COMPLETED => 0,
       ScheduledTask::STATUS_PAUSED => 0,
@@ -40,7 +40,7 @@ class State
   /**
    * @return array
    */
-  function getLatestTasks(
+  public function getLatestTasks(
     $type = null,
     $statuses = [
       ScheduledTask::STATUS_COMPLETED,
diff --git a/lib/Tasks/Subscribers.php b/lib/Tasks/Subscribers.php
index fe7f8c6f1d..a182edc139 100644
--- a/lib/Tasks/Subscribers.php
+++ b/lib/Tasks/Subscribers.php
@@ -12,15 +12,15 @@ class Subscribers {
     $this->task = $task;
   }
 
-  function setSubscribers(array $subscriber_ids) {
+  public function setSubscribers(array $subscriber_ids) {
     ScheduledTaskSubscriber::setSubscribers($this->task->id, $subscriber_ids);
   }
 
-  function getSubscribers() {
+  public function getSubscribers() {
     return ScheduledTaskSubscriber::where('task_id', $this->task->id);
   }
 
-  function isSubscriberProcessed($subscriber_id) {
+  public function isSubscriberProcessed($subscriber_id) {
     $subscriber = $this->getSubscribers()
       ->where('subscriber_id', $subscriber_id)
       ->where('processed', ScheduledTaskSubscriber::STATUS_PROCESSED)
@@ -28,20 +28,20 @@ class Subscribers {
     return !empty($subscriber);
   }
 
-  function removeSubscribers(array $subscribers_to_remove) {
+  public function removeSubscribers(array $subscribers_to_remove) {
     $this->getSubscribers()
       ->whereIn('subscriber_id', $subscribers_to_remove)
       ->deleteMany();
     $this->checkCompleted();
   }
 
-  function removeAllSubscribers() {
+  public function removeAllSubscribers() {
     $this->getSubscribers()
       ->deleteMany();
     $this->checkCompleted();
   }
 
-  function updateProcessedSubscribers(array $processed_subscribers) {
+  public function updateProcessedSubscribers(array $processed_subscribers) {
     if (!empty($processed_subscribers)) {
       $this->getSubscribers()
         ->whereIn('subscriber_id', $processed_subscribers)
@@ -52,7 +52,7 @@ class Subscribers {
     $this->checkCompleted();
   }
 
-  function saveSubscriberError($subcriber_id, $error_message) {
+  public function saveSubscriberError($subcriber_id, $error_message) {
     $this->getSubscribers()
       ->where('subscriber_id', $subcriber_id)
       ->findResultSet()
diff --git a/lib/Tasks/Subscribers/BatchIterator.php b/lib/Tasks/Subscribers/BatchIterator.php
index f6832307c9..b483bd7c65 100644
--- a/lib/Tasks/Subscribers/BatchIterator.php
+++ b/lib/Tasks/Subscribers/BatchIterator.php
@@ -12,7 +12,7 @@ class BatchIterator implements \Iterator, \Countable {
   private $last_processed_id = 0;
   private $batch_last_id;
 
-  function __construct($task_id, $batch_size) {
+  public function __construct($task_id, $batch_size) {
     if ($task_id <= 0) {
       throw new \Exception('Task ID must be greater than zero');
     } elseif ($batch_size <= 0) {
@@ -22,11 +22,11 @@ class BatchIterator implements \Iterator, \Countable {
     $this->batch_size = (int)$batch_size;
   }
 
-  function rewind() {
+  public function rewind() {
     $this->last_processed_id = 0;
   }
 
-  function current() {
+  public function current() {
     $subscribers = $this->getSubscribers()
       ->orderByAsc('subscriber_id')
       ->limit($this->batch_size)
@@ -36,19 +36,19 @@ class BatchIterator implements \Iterator, \Countable {
     return $subscribers;
   }
 
-  function key() {
+  public function key() {
     return null;
   }
 
-  function next() {
+  public function next() {
     $this->last_processed_id = $this->batch_last_id;
   }
 
-  function valid() {
+  public function valid() {
     return $this->count() > 0;
   }
 
-  function count() {
+  public function count() {
     return $this->getSubscribers()->count();
   }
 
diff --git a/lib/Tracy/ApiPanel/ApiPanel.php b/lib/Tracy/ApiPanel/ApiPanel.php
index 66681e9c43..a9306e2299 100644
--- a/lib/Tracy/ApiPanel/ApiPanel.php
+++ b/lib/Tracy/ApiPanel/ApiPanel.php
@@ -23,25 +23,25 @@ class ApiPanel implements IBarPanel {
   /** @var ReflectionClass */
   protected $endpoint_reflection;
 
-  function __construct($endpoint, $request_method, $request_data) {
+  public function __construct($endpoint, $request_method, $request_data) {
     $this->endpoint = $endpoint;
     $this->request_method = $request_method;
     $this->request_data = $request_data;
     $this->endpoint_reflection = new ReflectionClass($endpoint);
   }
 
-  function getTab() {
+  public function getTab() {
     $img = '<svg height="128px" id="Layer_1" style="enable-background:new 0 0 128 128;" version="1.1" viewBox="0 0 128 128" width="128px" xml:space="preserve" xmlns="http://www.w3.org/2000/svg"><g><g><g><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-linecap:square;stroke-miterlimit:10;" x1="63.185" x2="37.821" y1="84.061" y2="109.423"/><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-linecap:square;stroke-miterlimit:10;" x1="37.821" x2="12.456" y1="109.423" y2="84.061"/></g><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-miterlimit:10;" x1="37.821" x2="37.821" y1="109.423" y2="9.801"/></g><g><g><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-linecap:square;stroke-miterlimit:10;" x1="64.815" x2="90.181" y1="44.241" y2="18.877"/><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-linecap:square;stroke-miterlimit:10;" x1="90.181" x2="115.544" y1="18.877" y2="44.241"/></g><line style="fill:none;stroke:#2F3435;stroke-width:12;stroke-miterlimit:10;" x1="90.181" x2="90.181" y1="18.877" y2="118.199"/></g></g></svg>';
     return $img . '<span class="tracy-label" >' . $this->getEndpointName() . '</span>';
   }
 
-  function getPanel() {
+  public function getPanel() {
     ob_start();
     require __DIR__ . '/api-panel.phtml';
     return ob_get_clean();
   }
 
-  static function init($endpoint, $request_method, $request_data) {
+  public static function init($endpoint, $request_method, $request_data) {
     Debugger::getBar()->addPanel(new ApiPanel($endpoint, $request_method, $request_data));
   }
 
diff --git a/lib/Tracy/DIPanel/DIPanel.php b/lib/Tracy/DIPanel/DIPanel.php
index cf066e8dc9..479d700116 100644
--- a/lib/Tracy/DIPanel/DIPanel.php
+++ b/lib/Tracy/DIPanel/DIPanel.php
@@ -22,7 +22,7 @@ class DIPanel implements IBarPanel {
   /** @var string[][] */
   private $arguments_flattened = [];
 
-  function getTab() {
+  public function getTab() {
     $this->loadServices();
     $img = '<img
       src="data:image/png;base64,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"
@@ -31,13 +31,13 @@ class DIPanel implements IBarPanel {
     return $img . '<span class="tracy-label" >' . count($this->free_services) . ' + ' . count($this->premium_services) . ' services</span>';
   }
 
-  function getPanel() {
+  public function getPanel() {
     ob_start();
     require __DIR__ . '/di-panel.phtml';
     return ob_get_clean();
   }
 
-  static function init() {
+  public static function init() {
     Debugger::getBar()->addPanel(new DIPanel());
   }
 
diff --git a/lib/Tracy/DoctrinePanel/DoctrinePanel.php b/lib/Tracy/DoctrinePanel/DoctrinePanel.php
index cd2412a419..8cc9d42191 100644
--- a/lib/Tracy/DoctrinePanel/DoctrinePanel.php
+++ b/lib/Tracy/DoctrinePanel/DoctrinePanel.php
@@ -16,12 +16,12 @@ class DoctrinePanel implements IBarPanel {
   /** @var DebugStack */
   private $sql_logger;
 
-  function __construct(Configuration $doctrine_configuration) {
+  public function __construct(Configuration $doctrine_configuration) {
     $this->sql_logger = new DebugStack();
     $doctrine_configuration->setSQLLogger($this->sql_logger);
   }
 
-  function getTab() {
+  public function getTab() {
     $queries = $this->sql_logger->queries;
     $count = count($queries);
     $count_suffix = $count === 1 ? 'query' : 'queries';
@@ -34,13 +34,13 @@ class DoctrinePanel implements IBarPanel {
     return $img . '<span class="tracy-label" >' . "$count $count_suffix / $time ms" . '</span>';
   }
 
-  function getPanel() {
+  public function getPanel() {
     ob_start();
     require __DIR__ . '/doctrine-panel.phtml';
     return ob_get_clean();
   }
 
-  static function init(EntityManagerInterface $entity_manager) {
+  public static function init(EntityManagerInterface $entity_manager) {
     Debugger::getBar()->addPanel(new DoctrinePanel($entity_manager->getConnection()->getConfiguration()));
   }
 
diff --git a/lib/Twig/Assets.php b/lib/Twig/Assets.php
index b82bbfa45a..b752466d11 100644
--- a/lib/Twig/Assets.php
+++ b/lib/Twig/Assets.php
@@ -10,11 +10,11 @@ class Assets extends AbstractExtension {
   const CDN_URL = 'https://ps.w.org/mailpoet/';
   private $_globals;
 
-  function __construct($globals) {
+  public function __construct($globals) {
     $this->_globals = $globals;
   }
 
-  function getFunctions() {
+  public function getFunctions() {
     return [
       new TwigFunction(
         'stylesheet',
@@ -44,7 +44,7 @@ class Assets extends AbstractExtension {
     ];
   }
 
-  function generateStylesheet() {
+  public function generateStylesheet() {
     $stylesheets = func_get_args();
     $output = [];
 
@@ -59,7 +59,7 @@ class Assets extends AbstractExtension {
     return join("\n", $output);
   }
 
-  function generateJavascript() {
+  public function generateJavascript() {
     $scripts = func_get_args();
     $output = [];
 
@@ -73,7 +73,7 @@ class Assets extends AbstractExtension {
     return join("\n", $output);
   }
 
-  function getJavascriptScriptUrl($script) {
+  public function getJavascriptScriptUrl($script) {
     return sprintf(
       '%s/%s/%s',
       $this->_globals['assets_url'],
@@ -82,21 +82,21 @@ class Assets extends AbstractExtension {
     );
   }
 
-  function generateImageUrl($path) {
+  public function generateImageUrl($path) {
     return $this->appendVersionToUrl(
       $this->_globals['assets_url'] . '/img/' . $path
     );
   }
 
-  function appendVersionToUrl($url) {
+  public function appendVersionToUrl($url) {
     return WPFunctions::get()->addQueryArg('mailpoet_version', $this->_globals['version'], $url);
   }
 
-  function getAssetFileName($manifest, $asset) {
+  public function getAssetFileName($manifest, $asset) {
     return (!empty($manifest[$asset])) ? $manifest[$asset] : $asset;
   }
 
-  function generateCdnUrl($path) {
+  public function generateCdnUrl($path) {
     $useCdn = defined('MAILPOET_USE_CDN') ? MAILPOET_USE_CDN : true;
     return ($useCdn ? self::CDN_URL : $this->_globals['base_url'] . '/plugin_repository/') . "assets/$path";
   }
diff --git a/lib/Twig/Filters.php b/lib/Twig/Filters.php
index d8d21e88a2..51b0d43c0d 100644
--- a/lib/Twig/Filters.php
+++ b/lib/Twig/Filters.php
@@ -7,11 +7,11 @@ use MailPoetVendor\Twig\TwigFilter;
 
 class Filters extends AbstractExtension {
 
-  function getName() {
+  public function getName() {
     return 'filters';
   }
 
-  function getFilters() {
+  public function getFilters() {
     return [
       new TwigFilter(
         'intval',
diff --git a/lib/Twig/Functions.php b/lib/Twig/Functions.php
index 30ca57021a..66c86481e9 100644
--- a/lib/Twig/Functions.php
+++ b/lib/Twig/Functions.php
@@ -33,7 +33,7 @@ class Functions extends AbstractExtension {
     $this->referral_url_decorator = new UrlDecorator($this->wp, $this->settings);
   }
 
-  function getFunctions() {
+  public function getFunctions() {
     return [
       new TwigFunction(
         'json_encode',
@@ -158,7 +158,7 @@ class Functions extends AbstractExtension {
     ];
   }
 
-  function getSendingFrequency() {
+  public function getSendingFrequency() {
     $args = func_get_args();
     $value = (int)array_shift($args);
 
@@ -194,31 +194,31 @@ class Functions extends AbstractExtension {
     }
   }
 
-  function getWPDateFormat() {
+  public function getWPDateFormat() {
     return $this->wp->getOption('date_format') ?: 'F j, Y';
   }
 
-  function getWPStartOfWeek() {
+  public function getWPStartOfWeek() {
     return $this->wp->getOption('start_of_week') ?: 0;
   }
 
-  function getMailPoetVersion() {
+  public function getMailPoetVersion() {
     return MAILPOET_VERSION;
   }
 
-  function getMailPoetPremiumVersion() {
+  public function getMailPoetPremiumVersion() {
     return (defined('MAILPOET_PREMIUM_VERSION')) ? MAILPOET_PREMIUM_VERSION : false;
   }
 
-  function getWPTimeFormat() {
+  public function getWPTimeFormat() {
     return $this->wp->getOption('time_format') ?: 'g:i a';
   }
 
-  function getWPDateTimeFormat() {
+  public function getWPDateTimeFormat() {
     return sprintf('%s %s', $this->getWPDateFormat(), $this->getWPTimeFormat());
   }
 
-  function params($key = null) {
+  public function params($key = null) {
     $args = $this->wp->stripslashesDeep($_GET);
     if (array_key_exists($key, $args)) {
       return $args[$key];
@@ -226,29 +226,29 @@ class Functions extends AbstractExtension {
     return null;
   }
 
-  function installedInLastTwoWeeks() {
+  public function installedInLastTwoWeeks() {
     $max_number_of_weeks = 2;
     $installed_at = Carbon::createFromFormat('Y-m-d H:i:s', $this->settings->get('installed_at'));
     return $installed_at->diffInWeeks(Carbon::now()) < $max_number_of_weeks;
   }
 
-  function isRtl() {
+  public function isRtl() {
     return $this->wp->isRtl();
   }
 
-  function getTwoLettersLocale() {
+  public function getTwoLettersLocale() {
     return explode('_', $this->wp->getLocale())[0];
   }
 
-  function getFreeDomains() {
+  public function getFreeDomains() {
     return FreeDomains::FREE_DOMAINS;
   }
 
-  function isWoocommerceActive() {
+  public function isWoocommerceActive() {
     return $this->woocommerce_helper->isWooCommerceActive();
   }
 
-  function openedStatsColor($opened) {
+  public function openedStatsColor($opened) {
     if ($opened > 30) {
       return '#2993ab';
     } elseif ($opened > 10) {
@@ -258,7 +258,7 @@ class Functions extends AbstractExtension {
     }
   }
 
-  function clickedStatsColor($clicked) {
+  public function clickedStatsColor($clicked) {
     if ($clicked > 3) {
       return '#2993ab';
     } elseif ($clicked > 1) {
@@ -268,7 +268,7 @@ class Functions extends AbstractExtension {
     }
   }
 
-  function openedStatsText($opened) {
+  public function openedStatsText($opened) {
     if ($opened > 30) {
       return __('EXCELLENT', 'mailpoet');
     } elseif ($opened > 10) {
@@ -278,7 +278,7 @@ class Functions extends AbstractExtension {
     }
   }
 
-  function clickedStatsText($clicked) {
+  public function clickedStatsText($clicked) {
     if ($clicked > 3) {
       return __('EXCELLENT', 'mailpoet');
     } elseif ($clicked > 1) {
@@ -288,7 +288,7 @@ class Functions extends AbstractExtension {
     }
   }
 
-  function addReferralId($url) {
+  public function addReferralId($url) {
     return $this->referral_url_decorator->decorate($url);
   }
 }
diff --git a/lib/Twig/I18n.php b/lib/Twig/I18n.php
index 4629a6d2a8..e5abfe3986 100644
--- a/lib/Twig/I18n.php
+++ b/lib/Twig/I18n.php
@@ -11,12 +11,12 @@ class I18n extends AbstractExtension {
 
   private $_text_domains;
 
-  function __construct($text_domain) {
+  public function __construct($text_domain) {
     // set text domain
     $this->_text_domains = [$text_domain, 'woocommerce'];
   }
 
-  function getFunctions() {
+  public function getFunctions() {
     // twig custom functions
     $twig_functions = [];
     // list of WP functions to map
@@ -39,7 +39,7 @@ class I18n extends AbstractExtension {
     return $twig_functions;
   }
 
-  function localize() {
+  public function localize() {
     $args = func_get_args();
     $translations = array_shift($args);
     $output = [];
@@ -53,30 +53,30 @@ class I18n extends AbstractExtension {
     return join("\n", $output);
   }
 
-  function translate() {
+  public function translate() {
     $args = func_get_args();
 
     return call_user_func_array('__', $this->setTextDomain($args));
   }
 
-  function pluralize() {
+  public function pluralize() {
     $args = func_get_args();
 
     return call_user_func_array('_n', $this->setTextDomain($args));
   }
 
-  function translateWithContext() {
+  public function translateWithContext() {
     $args = func_get_args();
 
     return call_user_func_array('_x', $this->setTextDomain($args));
   }
 
-  function getLocale() {
+  public function getLocale() {
     $localizer = new Localizer;
     return $localizer->locale();
   }
 
-  function date() {
+  public function date() {
     $args = func_get_args();
     $date = (isset($args[0])) ? $args[0] : null;
     $date_format = (isset($args[1])) ? $args[1] : WPFunctions::get()->getOption('date_format');
diff --git a/lib/Twig/Polls.php b/lib/Twig/Polls.php
index 2319ed79dc..1ec106909c 100644
--- a/lib/Twig/Polls.php
+++ b/lib/Twig/Polls.php
@@ -30,13 +30,13 @@ class Polls extends AbstractExtension {
     ];
   }
 
-  function getPollsData() {
+  public function getPollsData() {
     return [
       'mta_method' => $this->settings->get('mta.method'),
     ];
   }
 
-  function getPollsVisibility() {
+  public function getPollsVisibility() {
     return [
       'show_poll_success_delivery_preview' => $this->settings->get('show_poll_success_delivery_preview'),
     ];
diff --git a/lib/Util/ConflictResolver.php b/lib/Util/ConflictResolver.php
index c370c3a6bb..7f316d7513 100644
--- a/lib/Util/ConflictResolver.php
+++ b/lib/Util/ConflictResolver.php
@@ -32,7 +32,7 @@ class ConflictResolver {
     ],
   ];
 
-  function init() {
+  public function init() {
     WPFunctions::get()->addAction(
       'mailpoet_conflict_resolver_router_url_query_parameters',
       [
@@ -70,12 +70,12 @@ class ConflictResolver {
     );
   }
 
-  function resolveRouterUrlQueryParametersConflict() {
+  public function resolveRouterUrlQueryParametersConflict() {
     // prevents other plugins from overtaking URL query parameters 'action=' and 'endpoint='
     unset($_GET['endpoint'], $_GET['action']);
   }
 
-  function resolveStylesConflict() {
+  public function resolveStylesConflict() {
     $_this = $this;
     $_this->permitted_assets_locations['styles'] = WPFunctions::get()->applyFilters('mailpoet_conflict_resolver_whitelist_style', $_this->permitted_assets_locations['styles']);
     // unload all styles except from the list of allowed
@@ -106,7 +106,7 @@ class ConflictResolver {
     WPFunctions::get()->addAction('admin_print_footer_scripts', $dequeue_styles, $execute_first);
   }
 
-  function resolveScriptsConflict() {
+  public function resolveScriptsConflict() {
     $_this = $this;
     $_this->permitted_assets_locations['scripts'] = WPFunctions::get()->applyFilters('mailpoet_conflict_resolver_whitelist_script', $_this->permitted_assets_locations['scripts']);
     // unload all scripts except from the list of allowed
@@ -135,7 +135,7 @@ class ConflictResolver {
     WPFunctions::get()->addAction('admin_print_footer_scripts', $dequeue_scripts, $execute_first);
   }
 
-  function resolveEditorConflict() {
+  public function resolveEditorConflict() {
 
     // mark editor as already enqueued to prevent loading its assets
     // when wp_enqueue_editor() used by some other plugin
@@ -161,7 +161,7 @@ class ConflictResolver {
     });
   }
 
-  function resolveTinyMceConflict() {
+  public function resolveTinyMceConflict() {
     // WordPress TinyMCE scripts may not get enqueued as scripts when some plugins use wp_editor()
     // or wp_enqueue_editor(). Instead, they are printed inside the footer script print actions.
     // To unload TinyMCE we need to remove those actions.
diff --git a/lib/Util/Cookies.php b/lib/Util/Cookies.php
index e3705bfee6..b513fbc99e 100644
--- a/lib/Util/Cookies.php
+++ b/lib/Util/Cookies.php
@@ -13,7 +13,7 @@ class Cookies {
     'httponly' => false,
   ];
 
-  function set($name, $value, array $options = []) {
+  public function set($name, $value, array $options = []) {
     $options = $options + self::DEFAULT_OPTIONS;
     $value = json_encode($value, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
     $error = json_last_error();
@@ -33,7 +33,7 @@ class Cookies {
     );
   }
 
-  function get($name) {
+  public function get($name) {
     if (!array_key_exists($name, $_COOKIE)) {
       return null;
     }
@@ -45,7 +45,7 @@ class Cookies {
     return $value;
   }
 
-  function delete($name) {
+  public function delete($name) {
     unset($_COOKIE[$name]);
   }
 }
diff --git a/lib/Util/DOM.php b/lib/Util/DOM.php
index 9fabb6d975..077b654344 100644
--- a/lib/Util/DOM.php
+++ b/lib/Util/DOM.php
@@ -11,7 +11,7 @@ class DOM {
    * ancestor and splitting left and right siblings into subtrees along
    * the way, retaining order and nesting level.
    */
-  static function splitOn(DomNode $bound, DomNode $cut_element) {
+  public static function splitOn(DomNode $bound, DomNode $cut_element) {
     $ignore_text_and_comment_nodes = false;
     for ($parent = $cut_element->parent; $bound != $parent; $parent = $grandparent) {
       // Clone parent node without children, but with attributes
@@ -32,7 +32,7 @@ class DOM {
     }
   }
 
-  static function findTopAncestor(DomNode $item) {
+  public static function findTopAncestor(DomNode $item) {
     while ($item->parent->parent !== null) {
       $item = $item->parent;
     }
diff --git a/lib/Util/FreeDomains.php b/lib/Util/FreeDomains.php
index 8768646606..553678508b 100644
--- a/lib/Util/FreeDomains.php
+++ b/lib/Util/FreeDomains.php
@@ -53,7 +53,7 @@ class FreeDomains {
     'yahoo.com.br', 'hotmail.com.br', 'outlook.com.br', 'uol.com.br', 'bol.com.br', 'terra.com.br', 'ig.com.br', 'itelefonica.com.br', 'r7.com', 'zipmail.com.br', 'globo.com', 'globomail.com', 'oi.com.br',
   ];
 
-  function isEmailOnFreeDomain($email) {
+  public function isEmailOnFreeDomain($email) {
     $email_parts = explode('@', $email);
     $domain = end($email_parts);
     return in_array($domain, self::FREE_DOMAINS);
diff --git a/lib/Util/Helpers.php b/lib/Util/Helpers.php
index b530495b88..87c115f9ae 100644
--- a/lib/Util/Helpers.php
+++ b/lib/Util/Helpers.php
@@ -6,13 +6,13 @@ class Helpers {
   const DIVIDER = '***MailPoet***';
   const LINK_TAG = 'link';
 
-  static function isJson($string) {
+  public static function isJson($string) {
     if (!is_string($string)) return false;
     json_decode($string);
     return json_last_error() == JSON_ERROR_NONE;
   }
 
-  static function replaceLinkTags($source, $link = false, $attributes = [], $link_tag = false) {
+  public static function replaceLinkTags($source, $link = false, $attributes = [], $link_tag = false) {
     if (!$link) return $source;
     $link_tag = ($link_tag) ? $link_tag : self::LINK_TAG;
     $attributes = array_map(function($key) use ($attributes) {
@@ -31,7 +31,7 @@ class Helpers {
     return preg_replace('/\s+/', ' ', $source);
   }
 
-  static function getMaxPostSize($bytes = false) {
+  public static function getMaxPostSize($bytes = false) {
     $maxPostSize = ini_get('post_max_size');
     if (!$bytes) return $maxPostSize;
     if ($maxPostSize === false) {
@@ -52,7 +52,7 @@ class Helpers {
     }
   }
 
-  static function flattenArray($array) {
+  public static function flattenArray($array) {
     if (!$array) return;
     $flattened_array = [];
     array_walk_recursive($array, function ($a) use (&$flattened_array) {
@@ -61,7 +61,7 @@ class Helpers {
     return $flattened_array;
   }
 
-  static function underscoreToCamelCase($str, $capitalise_first_char = false) {
+  public static function underscoreToCamelCase($str, $capitalise_first_char = false) {
     if ($capitalise_first_char) {
       $str[0] = strtoupper($str[0]);
     }
@@ -70,28 +70,28 @@ class Helpers {
     }, $str);
   }
 
-  static function camelCaseToUnderscore($str) {
+  public static function camelCaseToUnderscore($str) {
     $str[0] = strtolower($str[0]);
     return preg_replace_callback('/([A-Z])/', function ($c) {
       return "_" . strtolower($c[1]);
     }, $str);
   }
 
-  static function joinObject($object = []) {
+  public static function joinObject($object = []) {
     return implode(self::DIVIDER, $object);
   }
 
-  static function splitObject($object = []) {
+  public static function splitObject($object = []) {
     return explode(self::DIVIDER, $object);
   }
 
-  static function getIP() {
+  public static function getIP() {
     return (isset($_SERVER['REMOTE_ADDR']))
       ? $_SERVER['REMOTE_ADDR']
       : null;
   }
 
-  static function recursiveTrim($value) {
+  public static function recursiveTrim($value) {
     if (is_array($value))
       return array_map([__CLASS__, 'recursiveTrim'], $value);
     if (is_string($value))
diff --git a/lib/Util/Installation.php b/lib/Util/Installation.php
index 6cc4f4a00c..02d5956df0 100644
--- a/lib/Util/Installation.php
+++ b/lib/Util/Installation.php
@@ -15,12 +15,12 @@ class Installation {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function isNewInstallation() {
+  public function isNewInstallation() {
     $installed_at = $this->settings->get('installed_at');
     if (is_null($installed_at)) {
       return true;
diff --git a/lib/Util/License/Features/Subscribers.php b/lib/Util/License/Features/Subscribers.php
index 71c199e9ed..d06aa1a3ee 100644
--- a/lib/Util/License/Features/Subscribers.php
+++ b/lib/Util/License/Features/Subscribers.php
@@ -17,12 +17,12 @@ class Subscribers {
   /** @var SubscribersRepository */
   private $subscribers_repository;
 
-  function __construct(SettingsController $settings, SubscribersRepository $subscribers_repository) {
+  public function __construct(SettingsController $settings, SubscribersRepository $subscribers_repository) {
     $this->settings = $settings;
     $this->subscribers_repository = $subscribers_repository;
   }
 
-  function check() {
+  public function check() {
     $subscribers_count = $this->subscribers_repository->getTotalSubscribers();
     $has_mss_key = !empty($this->settings->get(Bridge::API_KEY_SETTING_NAME));
     $has_premium_key = !empty($this->settings->get(Bridge::PREMIUM_KEY_SETTING_NAME));
@@ -30,7 +30,7 @@ class Subscribers {
     return $subscribers_count > $this->getSubscribersLimit();
   }
 
-  function getSubscribersLimit() {
+  public function getSubscribersLimit() {
     $installation_time = strtotime($this->settings->get('installed_at'));
     $old_user = $installation_time < strtotime(self::NEW_LIMIT_DATE);
     return $old_user ? self::SUBSCRIBERS_OLD_LIMIT : self::SUBSCRIBERS_NEW_LIMIT;
diff --git a/lib/Util/License/License.php b/lib/Util/License/License.php
index da7b7a6773..d80b8d126c 100644
--- a/lib/Util/License/License.php
+++ b/lib/Util/License/License.php
@@ -5,7 +5,7 @@ namespace MailPoet\Util\License;
 class License {
   const FREE_PREMIUM_SUBSCRIBERS_LIMIT = 1000;
 
-  static function getLicense($license = false) {
+  public static function getLicense($license = false) {
     if (!$license) {
       $license = defined('MAILPOET_PREMIUM_LICENSE') ?
       MAILPOET_PREMIUM_LICENSE :
diff --git a/lib/Util/Notices/AfterMigrationNotice.php b/lib/Util/Notices/AfterMigrationNotice.php
index 266d6c4e81..9eb71e4be8 100644
--- a/lib/Util/Notices/AfterMigrationNotice.php
+++ b/lib/Util/Notices/AfterMigrationNotice.php
@@ -13,19 +13,19 @@ class AfterMigrationNotice {
   /** @var SettingsController */
   private $settings;
 
-  function __construct() {
+  public function __construct() {
     $this->settings = SettingsController::getInstance();
   }
 
-  function enable() {
+  public function enable() {
     $this->settings->set(self::OPTION_NAME, true);
   }
 
-  function disable() {
+  public function disable() {
     $this->settings->set(self::OPTION_NAME, false);
   }
 
-  function init($should_display) {
+  public function init($should_display) {
     if ($should_display && $this->settings->get(self::OPTION_NAME, false)) {
       return $this->display();
     }
diff --git a/lib/Util/Notices/BlackFridayNotice.php b/lib/Util/Notices/BlackFridayNotice.php
index d5574780cd..0d05685eb2 100644
--- a/lib/Util/Notices/BlackFridayNotice.php
+++ b/lib/Util/Notices/BlackFridayNotice.php
@@ -11,7 +11,7 @@ class BlackFridayNotice {
   const OPTION_NAME = 'dismissed-black-friday-notice';
   const DISMISS_NOTICE_TIMEOUT_SECONDS = 2592000; // 30 days
 
-  function init($should_display) {
+  public function init($should_display) {
     $should_display = $should_display
       && (time() <= strtotime('2019-11-30 23:59:59'))
       && (time() >= strtotime('2019-11-08 00:00:00'))
@@ -36,7 +36,7 @@ class BlackFridayNotice {
     WPNotice::displaySuccess($header . $body . $link, $extra_classes, self::OPTION_NAME);
   }
 
-  function disable() {
+  public function disable() {
     WPFunctions::get()->setTransient(self::OPTION_NAME, true, self::DISMISS_NOTICE_TIMEOUT_SECONDS);
   }
 
diff --git a/lib/Util/Notices/InactiveSubscribersNotice.php b/lib/Util/Notices/InactiveSubscribersNotice.php
index 520c220795..c46a0d6e78 100644
--- a/lib/Util/Notices/InactiveSubscribersNotice.php
+++ b/lib/Util/Notices/InactiveSubscribersNotice.php
@@ -18,12 +18,12 @@ class InactiveSubscribersNotice {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function init($should_display) {
+  public function init($should_display) {
     if (!$should_display || !$this->settings->get(self::OPTION_NAME, true)) {
       return;
     }
@@ -41,7 +41,7 @@ class InactiveSubscribersNotice {
     return $this->display($inactive_subscribers_count);
   }
 
-  function disable() {
+  public function disable() {
     $this->settings->set(self::OPTION_NAME, false);
   }
 
diff --git a/lib/Util/Notices/PHPVersionWarnings.php b/lib/Util/Notices/PHPVersionWarnings.php
index 6e7d141cf2..f5a21d8d5d 100644
--- a/lib/Util/Notices/PHPVersionWarnings.php
+++ b/lib/Util/Notices/PHPVersionWarnings.php
@@ -11,17 +11,17 @@ class PHPVersionWarnings {
   const DISMISS_NOTICE_TIMEOUT_SECONDS = 2592000; // 30 days
   const OPTION_NAME = 'dismissed-php-version-outdated-notice';
 
-  function init($php_version, $should_display) {
+  public function init($php_version, $should_display) {
     if ($should_display && $this->isOutdatedPHPVersion($php_version)) {
       return $this->display($php_version);
     }
   }
 
-  function isOutdatedPHPVersion($php_version) {
+  public function isOutdatedPHPVersion($php_version) {
     return version_compare($php_version, '7.0', '<') && !get_transient(self::OPTION_NAME);
   }
 
-  function display($php_version) {
+  public function display($php_version) {
     $error_string = __('Your website is running on PHP %s which MailPoet does not officially support. Read our [link]simple PHP upgrade guide[/link] or let MailPoet’s support team upgrade it for you.', 'mailpoet');
     $error_string = sprintf($error_string, $php_version);
     $get_in_touch_string = __('[link]Yes, I want MailPoet to help me upgrade for free[/link]', 'mailpoet');
@@ -37,7 +37,7 @@ class PHPVersionWarnings {
     return Notice::displayWarning($error, $extra_classes, self::OPTION_NAME);
   }
 
-  function disable() {
+  public function disable() {
     WPFunctions::get()->setTransient(self::OPTION_NAME, true, self::DISMISS_NOTICE_TIMEOUT_SECONDS);
   }
 
diff --git a/lib/Util/Notices/PermanentNotices.php b/lib/Util/Notices/PermanentNotices.php
index 636dbe0231..568e9efbf9 100644
--- a/lib/Util/Notices/PermanentNotices.php
+++ b/lib/Util/Notices/PermanentNotices.php
@@ -71,7 +71,7 @@ class PermanentNotices {
     );
   }
 
-  function ajaxDismissNoticeHandler() {
+  public function ajaxDismissNoticeHandler() {
     if (!isset($_POST['type'])) return;
     switch ($_POST['type']) {
       case (PHPVersionWarnings::OPTION_NAME):
diff --git a/lib/Util/Notices/UnauthorizedEmailInNewslettersNotice.php b/lib/Util/Notices/UnauthorizedEmailInNewslettersNotice.php
index e418a72a39..b81183ba18 100644
--- a/lib/Util/Notices/UnauthorizedEmailInNewslettersNotice.php
+++ b/lib/Util/Notices/UnauthorizedEmailInNewslettersNotice.php
@@ -23,19 +23,19 @@ class UnauthorizedEmailInNewslettersNotice {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function init($should_display) {
+  public function init($should_display) {
     $validation_error = $this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING);
     if ($should_display && isset($validation_error['invalid_senders_in_newsletters'])) {
       return $this->display($validation_error);
     }
   }
 
-  function display($validation_error) {
+  public function display($validation_error) {
     $message = $this->getMessageText();
     $message .= $this->getNewslettersLinks($validation_error);
     $message .= $this->getAuthorizationLink($validation_error);
diff --git a/lib/Util/Notices/UnauthorizedEmailNotice.php b/lib/Util/Notices/UnauthorizedEmailNotice.php
index 5374f345db..9a3cf47374 100644
--- a/lib/Util/Notices/UnauthorizedEmailNotice.php
+++ b/lib/Util/Notices/UnauthorizedEmailNotice.php
@@ -19,19 +19,19 @@ class UnauthorizedEmailNotice {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(SettingsController $settings, WPFunctions $wp) {
+  public function __construct(SettingsController $settings, WPFunctions $wp) {
     $this->settings = $settings;
     $this->wp = $wp;
   }
 
-  function init($should_display) {
+  public function init($should_display) {
     $validation_error = $this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING);
     if ($should_display && isset($validation_error['invalid_sender_address'])) {
       return $this->display($validation_error);
     }
   }
 
-  function display($validation_error) {
+  public function display($validation_error) {
     $message = $this->getMessageText($validation_error);
     $message .= $this->getSettingsButtons($validation_error);
     $message .= $this->getAuthorizationLink($validation_error);
diff --git a/lib/Util/SecondLevelDomainNames.php b/lib/Util/SecondLevelDomainNames.php
index 2ce8f308e7..e627c92aea 100644
--- a/lib/Util/SecondLevelDomainNames.php
+++ b/lib/Util/SecondLevelDomainNames.php
@@ -4,7 +4,7 @@ namespace MailPoet\Util;
 
 class SecondLevelDomainNames {
 
-  function get($host) {
+  public function get($host) {
     if (preg_match('/[^.]*\.[^.]{2,3}(?:\.[^.]{2,3})?$/', $host, $matches)) {
       return $matches[0];
     }
diff --git a/lib/Util/Security.php b/lib/Util/Security.php
index daa5ab2fda..b1fa98c886 100644
--- a/lib/Util/Security.php
+++ b/lib/Util/Security.php
@@ -8,7 +8,7 @@ class Security {
   const HASH_LENGTH = 12;
   const UNSUBSCRIBE_TOKEN_LENGTH = 15;
 
-  static function generateToken($action = 'mailpoet_token') {
+  public static function generateToken($action = 'mailpoet_token') {
     return WPFunctions::get()->wpCreateNonce($action);
   }
 
@@ -19,7 +19,7 @@ class Security {
    * @param int $length Minimal lenght is 5
    * @return string
    */
-  static function generateRandomString($length = 5) {
+  public static function generateRandomString($length = 5) {
     $length = max(5, (int)$length);
     $string = base_convert(
       bin2hex(
@@ -37,7 +37,7 @@ class Security {
    * @param int $length Maximal length is 32
    * @return string
    */
-  static function generateHash($length = null) {
+  public static function generateHash($length = null) {
     $length = ($length) ? $length : self::HASH_LENGTH;
     $auth_key = '';
     if (defined('AUTH_KEY')) {
diff --git a/lib/Util/Url.php b/lib/Util/Url.php
index e3ba379770..18120d8aca 100644
--- a/lib/Util/Url.php
+++ b/lib/Util/Url.php
@@ -8,11 +8,11 @@ class Url {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp) {
+  public function __construct(WPFunctions $wp) {
     $this->wp = $wp;
   }
 
-  function getCurrentUrl() {
+  public function getCurrentUrl() {
     $home_url = parse_url($this->wp->homeUrl());
     $query_args = $this->wp->addQueryArg(null, null);
 
@@ -24,12 +24,12 @@ class Url {
     return $this->wp->homeUrl($query_args);
   }
 
-  function redirectTo($url = null) {
+  public function redirectTo($url = null) {
     $this->wp->wpSafeRedirect($url);
     exit();
   }
 
-  function redirectBack($params = []) {
+  public function redirectBack($params = []) {
     // check mailpoet_redirect parameter
     $referer = (isset($_POST['mailpoet_redirect'])
       ? $_POST['mailpoet_redirect']
@@ -50,7 +50,7 @@ class Url {
     exit();
   }
 
-  function redirectWithReferer($url = null) {
+  public function redirectWithReferer($url = null) {
     $current_url = $this->getCurrentUrl();
     $url = $this->wp->addQueryArg(
       [
diff --git a/lib/Util/pQuery/DomNode.php b/lib/Util/pQuery/DomNode.php
index e2cab3ebac..88775d7c43 100644
--- a/lib/Util/pQuery/DomNode.php
+++ b/lib/Util/pQuery/DomNode.php
@@ -5,11 +5,11 @@ namespace MailPoet\Util\pQuery;
 class DomNode extends \pQuery\DomNode {
   public $childClass = 'MailPoet\Util\pQuery\DomNode';
 
-  function getInnerText() {
+  public function getInnerText() {
     return html_entity_decode($this->toString(true, true, 1), ENT_NOQUOTES, 'UTF-8');
   }
 
-  function getOuterText() {
+  public function getOuterText() {
     return html_entity_decode($this->toString(), ENT_NOQUOTES, 'UTF-8');
   }
 }
diff --git a/lib/WP/DateTime.php b/lib/WP/DateTime.php
index afddbe218d..4c7d1629e9 100644
--- a/lib/WP/DateTime.php
+++ b/lib/WP/DateTime.php
@@ -13,42 +13,42 @@ class DateTime {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp = null) {
+  public function __construct(WPFunctions $wp = null) {
     if ($wp === null) {
       $wp = new WPFunctions();
     }
     $this->wp = $wp;
   }
 
-  function getTimeFormat() {
+  public function getTimeFormat() {
     $time_format = $this->wp->getOption('time_format');
     if (empty($time_format)) $time_format = self::DEFAULT_TIME_FORMAT;
     return $time_format;
   }
 
-  function getDateFormat() {
+  public function getDateFormat() {
     $date_format = $this->wp->getOption('date_format');
     if (empty($date_format)) $date_format = self::DEFAULT_DATE_FORMAT;
     return $date_format;
   }
 
-  function getCurrentTime($format=false) {
+  public function getCurrentTime($format=false) {
     if (empty($format)) $format = $this->getTimeFormat();
     return $this->wp->currentTime($format);
   }
 
-  function getCurrentDate($format=false) {
+  public function getCurrentDate($format=false) {
     if (empty($format)) $format = $this->getDateFormat();
     return $this->getCurrentTime($format);
   }
 
-  function formatTime($timestamp, $format=false) {
+  public function formatTime($timestamp, $format=false) {
     if (empty($format)) $format = $this->getTimeFormat();
 
     return date($format, $timestamp);
   }
 
-  function formatDate($timestamp, $format=false) {
+  public function formatDate($timestamp, $format=false) {
     if (empty($format)) $format = $this->getDateFormat();
 
     return date($format, $timestamp);
@@ -58,7 +58,7 @@ class DateTime {
    * Generates a list of time strings within an interval,
    * formatted and mapped from DEFAULT_TIME_FORMAT to WordPress time strings.
    */
-  function getTimeInterval(
+  public function getTimeInterval(
     $start_time='00:00:00',
     $time_step='+1 hour',
     $total_steps=24
diff --git a/lib/WP/Emoji.php b/lib/WP/Emoji.php
index d73c865e58..69985a81bb 100644
--- a/lib/WP/Emoji.php
+++ b/lib/WP/Emoji.php
@@ -8,21 +8,21 @@ class Emoji {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(WPFunctions $wp = null) {
+  public function __construct(WPFunctions $wp = null) {
     if ($wp === null) {
       $wp = new WPFunctions();
     }
     $this->wp = $wp;
   }
 
-  function encodeEmojisInBody($newsletter_rendered_body) {
+  public function encodeEmojisInBody($newsletter_rendered_body) {
     if (is_array($newsletter_rendered_body)) {
       return array_map([$this, 'encodeRenderedBodyForUTF8Column'], $newsletter_rendered_body);
     }
     return $this->encodeRenderedBodyForUTF8Column($newsletter_rendered_body);
   }
 
-  function decodeEmojisInBody($newsletter_rendered_body) {
+  public function decodeEmojisInBody($newsletter_rendered_body) {
     if (is_array($newsletter_rendered_body)) {
       return array_map([$this, 'decodeEntities'], $newsletter_rendered_body);
     }
@@ -37,7 +37,7 @@ class Emoji {
     );
   }
 
-  function encodeForUTF8Column($table, $field, $value) {
+  public function encodeForUTF8Column($table, $field, $value) {
     global $wpdb;
     $charset = $wpdb->get_col_charset($table, $field);
     if ($charset === 'utf8') {
@@ -46,7 +46,7 @@ class Emoji {
     return $value;
   }
 
-  function decodeEntities($content) {
+  public function decodeEntities($content) {
     // Based on WPFunctions::get()->wpStaticizeEmoji()
 
     // Loosely match the Emoji Unicode range.
diff --git a/lib/WP/Functions.php b/lib/WP/Functions.php
index 9c794140bc..132d7214e5 100644
--- a/lib/WP/Functions.php
+++ b/lib/WP/Functions.php
@@ -11,14 +11,14 @@ class Functions {
   /**
    * @return Functions
    */
-  static function get() {
+  public static function get() {
     if (self::$instance === null) {
       self::$instance = new Functions;
     }
     return self::$instance;
   }
 
-  static function set(Functions $instance) {
+  public static function set(Functions $instance) {
     self::$instance = $instance;
   }
 
@@ -27,7 +27,7 @@ class Functions {
    * @param mixed ...$args
    * @return mixed
    */
-  function doAction($tag, ...$args) {
+  public function doAction($tag, ...$args) {
     return call_user_func_array('do_action', func_get_args());
   }
 
@@ -36,7 +36,7 @@ class Functions {
    * @param mixed ...$args
    * @return mixed
    */
-  function applyFilters($tag, ...$args) {
+  public function applyFilters($tag, ...$args) {
     return call_user_func_array('apply_filters', func_get_args());
   }
 
@@ -47,42 +47,42 @@ class Functions {
    * @param int $accepted_args
    * @return boolean
    */
-  function addAction($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
+  public function addAction($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
     return call_user_func_array('add_action', func_get_args());
   }
 
-  function __($text, $domain = 'default') {
+  public function __($text, $domain = 'default') {
     return __($text, $domain);
   }
 
-  function _e($text, $domain = 'default') {
+  public function _e($text, $domain = 'default') {
     return _e($text, $domain);
   }
 
-  function _n($single, $plural, $number, $domain = 'default') {
+  public function _n($single, $plural, $number, $domain = 'default') {
     return _n($single, $plural, $number, $domain);
   }
 
-  function _x($text, $context, $domain = 'default') {
+  public function _x($text, $context, $domain = 'default') {
     return _x($text, $context, $domain);
   }
 
-  function addCommentMeta($comment_id, $meta_key, $meta_value, $unique = false) {
+  public function addCommentMeta($comment_id, $meta_key, $meta_value, $unique = false) {
     return add_comment_meta($comment_id, $meta_key, $meta_value, $unique);
   }
 
-  function addFilter($tag, callable $function_to_add, $priority = 10, $accepted_args = 1) {
+  public function addFilter($tag, callable $function_to_add, $priority = 10, $accepted_args = 1) {
     return add_filter($tag, $function_to_add, $priority, $accepted_args);
   }
 
   /**
    * @param bool|array $crop
    */
-  function addImageSize($name, $width = 0, $height = 0, $crop = false) {
+  public function addImageSize($name, $width = 0, $height = 0, $crop = false) {
     return add_image_size($name, $width, $height, $crop);
   }
 
-  function addMenuPage($page_title, $menu_title, $capability, $menu_slug, callable $function = null, $icon_url = '', $position = null) {
+  public function addMenuPage($page_title, $menu_title, $capability, $menu_slug, callable $function = null, $icon_url = '', $position = null) {
     if (is_null($function)) {
       $function = function () {
       };
@@ -90,163 +90,163 @@ class Functions {
     return add_menu_page($page_title, $menu_title, $capability, $menu_slug, $function, $icon_url, $position);
   }
 
-  function addQueryArg($key, $value = false, $url = false) {
+  public function addQueryArg($key, $value = false, $url = false) {
     return add_query_arg($key, $value, $url);
   }
 
-  function addScreenOption($option, $args = []) {
+  public function addScreenOption($option, $args = []) {
     return add_screen_option($option, $args);
   }
 
-  function addShortcode($tag, callable $callback) {
+  public function addShortcode($tag, callable $callback) {
     return add_shortcode($tag, $callback);
   }
 
-  function addSubmenuPage($parent_slug, $page_title, $menu_title, $capability, $menu_slug, callable $function) {
+  public function addSubmenuPage($parent_slug, $page_title, $menu_title, $capability, $menu_slug, callable $function) {
     return add_submenu_page($parent_slug, $page_title, $menu_title, $capability, $menu_slug, $function);
   }
 
-  function adminUrl($path = '', $scheme = 'admin') {
+  public function adminUrl($path = '', $scheme = 'admin') {
     return admin_url($path, $scheme);
   }
 
-  function currentFilter() {
+  public function currentFilter() {
     return current_filter();
   }
 
-  function currentTime($type, $gmt = false) {
+  public function currentTime($type, $gmt = false) {
     return current_time($type, $gmt);
   }
 
-  function currentUserCan($capability) {
+  public function currentUserCan($capability) {
     return current_user_can($capability);
   }
 
-  function dateI18n($dateformatstring, $timestamp_with_offset = false, $gmt = false) {
+  public function dateI18n($dateformatstring, $timestamp_with_offset = false, $gmt = false) {
     return date_i18n($dateformatstring, $timestamp_with_offset, $gmt);
   }
 
-  function deleteCommentMeta($comment_id, $meta_key, $meta_value = '') {
+  public function deleteCommentMeta($comment_id, $meta_key, $meta_value = '') {
     return delete_comment_meta($comment_id, $meta_key, $meta_value);
   }
 
-  function deleteOption($option) {
+  public function deleteOption($option) {
     return delete_option($option);
   }
 
-  function doShortcode($content, $ignore_html = false) {
+  public function doShortcode($content, $ignore_html = false) {
     return do_shortcode($content, $ignore_html);
   }
 
-  function escAttr($text) {
+  public function escAttr($text) {
     return esc_attr($text);
   }
 
-  function escHtml($text) {
+  public function escHtml($text) {
     return esc_html($text);
   }
 
-  function escSql($sql) {
+  public function escSql($sql) {
     return esc_sql($sql);
   }
 
-  function getBloginfo($show = '', $filter = 'raw') {
+  public function getBloginfo($show = '', $filter = 'raw') {
     return get_bloginfo($show, $filter);
   }
 
-  function getCategories($args = '') {
+  public function getCategories($args = '') {
     return get_categories($args);
   }
 
-  function getComment($comment = null, $output = OBJECT) {
+  public function getComment($comment = null, $output = OBJECT) {
     return get_comment($comment, $output);
   }
 
-  function getCommentMeta($comment_id, $key = '', $single = false) {
+  public function getCommentMeta($comment_id, $key = '', $single = false) {
     return get_comment_meta($comment_id, $key, $single);
   }
 
-  function getCurrentScreen() {
+  public function getCurrentScreen() {
     return get_current_screen();
   }
 
-  function getCurrentUserId() {
+  public function getCurrentUserId() {
     return get_current_user_id();
   }
 
-  function getDateFromGmt($string, $format = 'Y-m-d H:i:s') {
+  public function getDateFromGmt($string, $format = 'Y-m-d H:i:s') {
     return get_date_from_gmt($string, $format);
   }
 
-  function getEditProfileUrl($user_id = 0, $scheme = 'admin') {
+  public function getEditProfileUrl($user_id = 0, $scheme = 'admin') {
     return get_edit_profile_url($user_id, $scheme);
   }
 
-  function getEditableRoles() {
+  public function getEditableRoles() {
     return get_editable_roles();
   }
 
-  function getLocale() {
+  public function getLocale() {
     return get_locale();
   }
 
-  function getObjectTaxonomies($object, $output = 'names') {
+  public function getObjectTaxonomies($object, $output = 'names') {
     return get_object_taxonomies($object, $output);
   }
 
-  function getOption($option, $default = false) {
+  public function getOption($option, $default = false) {
     return get_option($option, $default);
   }
 
-  function getPages($args = []) {
+  public function getPages($args = []) {
     return get_pages($args);
   }
 
-  function getPermalink($post, $leavename = false) {
+  public function getPermalink($post, $leavename = false) {
     return get_permalink($post, $leavename);
   }
 
-  function getPluginPageHook($plugin_page, $parent_page) {
+  public function getPluginPageHook($plugin_page, $parent_page) {
     return get_plugin_page_hook($plugin_page, $parent_page);
   }
 
-  function getPluginUpdates() {
+  public function getPluginUpdates() {
     return get_plugin_updates();
   }
 
-  function getPlugins($plugin_folder = '') {
+  public function getPlugins($plugin_folder = '') {
     return get_plugins($plugin_folder);
   }
 
-  function getPost($post = null, $output = OBJECT, $filter = 'raw') {
+  public function getPost($post = null, $output = OBJECT, $filter = 'raw') {
     return get_post($post, $output, $filter);
   }
 
-  function getPostThumbnailId($post = null) {
+  public function getPostThumbnailId($post = null) {
     return get_post_thumbnail_id($post);
   }
 
-  function getPostTypes($args = [], $output = 'names', $operator = 'and') {
+  public function getPostTypes($args = [], $output = 'names', $operator = 'and') {
     return get_post_types($args, $output, $operator);
   }
 
-  function getPosts(array $args = null) {
+  public function getPosts(array $args = null) {
     return get_posts($args);
   }
 
-  function getRole($role) {
+  public function getRole($role) {
     return get_role($role);
   }
 
-  function getSiteOption($option, $default = false, $deprecated = true) {
+  public function getSiteOption($option, $default = false, $deprecated = true) {
     return get_site_option($option, $default, $deprecated);
   }
 
-  function getSiteUrl($blog_id = null, $path = '', $scheme = null) {
+  public function getSiteUrl($blog_id = null, $path = '', $scheme = null) {
     return get_site_url($blog_id, $path, $scheme);
   }
 
-  function getTemplatePart($slug, $name = null) {
+  public function getTemplatePart($slug, $name = null) {
     return get_template_part($slug, $name);
   }
 
@@ -255,73 +255,73 @@ class Functions {
    * @param string|array $deprecated
    * @return array|int|WP_Error
    */
-  function getTerms($args = [], $deprecated = '') {
+  public function getTerms($args = [], $deprecated = '') {
     return get_terms($args, $deprecated);
   }
 
   /**
    * @param int|false $user_id
    */
-  function getTheAuthorMeta($field = '', $user_id = false) {
+  public function getTheAuthorMeta($field = '', $user_id = false) {
     return get_the_author_meta($field, $user_id);
   }
 
   /**
    * @param  int|\WP_User $user_id
    */
-  function getUserLocale($user_id = 0) {
+  public function getUserLocale($user_id = 0) {
     return get_user_locale($user_id);
   }
 
-  function getUserMeta($user_id, $key = '', $single = false) {
+  public function getUserMeta($user_id, $key = '', $single = false) {
     return get_user_meta($user_id, $key, $single);
   }
 
-  function getUserdata($user_id) {
+  public function getUserdata($user_id) {
     return get_userdata($user_id);
   }
 
-  function getUserBy($field, $value) {
+  public function getUserBy($field, $value) {
     return get_user_by($field, $value);
   }
 
-  function hasFilter($tag, $function_to_check = false) {
+  public function hasFilter($tag, $function_to_check = false) {
     return has_filter($tag, $function_to_check);
   }
 
-  function homeUrl($path = '', $scheme = null) {
+  public function homeUrl($path = '', $scheme = null) {
     return home_url($path, $scheme);
   }
 
-  function includesUrl($path = '', $scheme = null) {
+  public function includesUrl($path = '', $scheme = null) {
     return includes_url($path, $scheme);
   }
 
-  function isAdmin() {
+  public function isAdmin() {
     return is_admin();
   }
 
-  function isEmail($email, $deprecated = false) {
+  public function isEmail($email, $deprecated = false) {
     return is_email($email, $deprecated);
   }
 
-  function isMultisite() {
+  public function isMultisite() {
     return is_multisite();
   }
 
-  function isPluginActive($plugin) {
+  public function isPluginActive($plugin) {
     return is_plugin_active($plugin);
   }
 
-  function isRtl() {
+  public function isRtl() {
     return is_rtl();
   }
 
-  function isSerialized($data, $strict = true) {
+  public function isSerialized($data, $strict = true) {
     return is_serialized($data, $strict);
   }
 
-  function isUserLoggedIn() {
+  public function isUserLoggedIn() {
     return is_user_logged_in();
   }
 
@@ -329,35 +329,35 @@ class Functions {
    * @param  string|false $deprecated
    * @param  string|false $plugin_rel_path
    */
-  function loadPluginTextdomain($domain, $deprecated = false, $plugin_rel_path = false) {
+  public function loadPluginTextdomain($domain, $deprecated = false, $plugin_rel_path = false) {
     return load_plugin_textdomain($domain, $deprecated, $plugin_rel_path);
   }
 
-  function loadTextdomain($domain, $mofile) {
+  public function loadTextdomain($domain, $mofile) {
     return load_textdomain($domain, $mofile);
   }
 
-  function numberFormatI18n($number, $decimals = 0) {
+  public function numberFormatI18n($number, $decimals = 0) {
     return number_format_i18n($number, $decimals);
   }
 
-  function pluginBasename($file) {
+  public function pluginBasename($file) {
     return plugin_basename($file);
   }
 
-  function pluginsUrl($path = '', $plugin = '') {
+  public function pluginsUrl($path = '', $plugin = '') {
     return plugins_url($path, $plugin);
   }
 
-  function registerActivationHook($file, $function) {
+  public function registerActivationHook($file, $function) {
     return register_activation_hook($file, $function);
   }
 
-  function registerPostType($post_type, $args = []) {
+  public function registerPostType($post_type, $args = []) {
     return register_post_type($post_type, $args);
   }
 
-  function registerWidget($widget) {
+  public function registerWidget($widget) {
     return register_widget($widget);
   }
 
@@ -366,199 +366,199 @@ class Functions {
    * @param callable $function_to_remove
    * @param int $priority
    */
-  function removeAction($tag, $function_to_remove, $priority = 10) {
+  public function removeAction($tag, $function_to_remove, $priority = 10) {
     return remove_action($tag, $function_to_remove, $priority);
   }
 
-  function removeAllActions($tag, $priority = false) {
+  public function removeAllActions($tag, $priority = false) {
     return remove_all_actions($tag, $priority);
   }
 
-  function removeAllFilters($tag, $priority = false) {
+  public function removeAllFilters($tag, $priority = false) {
     return remove_all_filters($tag, $priority);
   }
 
-  function removeFilter($tag, callable $function_to_remove, $priority = 10) {
+  public function removeFilter($tag, callable $function_to_remove, $priority = 10) {
     return remove_filter($tag, $function_to_remove, $priority);
   }
 
-  function removeShortcode($tag) {
+  public function removeShortcode($tag) {
     return remove_shortcode($tag);
   }
 
-  function selfAdminUrl($path = '', $scheme = 'admin') {
+  public function selfAdminUrl($path = '', $scheme = 'admin') {
     return self_admin_url($path, $scheme);
   }
 
-  function setTransient($transient, $value, $expiration) {
+  public function setTransient($transient, $value, $expiration) {
     return set_transient($transient, $value, $expiration);
   }
 
-  function getTransient($transient) {
+  public function getTransient($transient) {
     return get_transient($transient);
   }
 
-  function deleteTransient($transient) {
+  public function deleteTransient($transient) {
     return delete_transient($transient);
   }
 
-  function singlePostTitle($prefix = '', $display = true) {
+  public function singlePostTitle($prefix = '', $display = true) {
     return single_post_title($prefix, $display);
   }
 
-  function siteUrl($path = '', $scheme = null) {
+  public function siteUrl($path = '', $scheme = null) {
     return site_url($path, $scheme);
   }
 
-  function statusHeader($code, $description = '') {
+  public function statusHeader($code, $description = '') {
     return status_header($code, $description);
   }
 
-  function stripslashesDeep($value) {
+  public function stripslashesDeep($value) {
     return stripslashes_deep($value);
   }
 
-  function translate($text, $domain = 'default') {
+  public function translate($text, $domain = 'default') {
     return translate($text, $domain);
   }
 
-  function unloadTextdomain($domain) {
+  public function unloadTextdomain($domain) {
     return unload_textdomain($domain);
   }
 
-  function updateOption($option, $value, $autoload = null) {
+  public function updateOption($option, $value, $autoload = null) {
     return update_option($option, $value, $autoload);
   }
 
-  function wpAddInlineScript($handle, $data, $position = 'after') {
+  public function wpAddInlineScript($handle, $data, $position = 'after') {
     return wp_add_inline_script($handle, $data, $position);
   }
 
-  function wpCreateNonce($action = -1) {
+  public function wpCreateNonce($action = -1) {
     return wp_create_nonce($action);
   }
 
-  function wpDequeueScript($handle) {
+  public function wpDequeueScript($handle) {
     return wp_dequeue_script($handle);
   }
 
-  function wpDequeueStyle($handle) {
+  public function wpDequeueStyle($handle) {
     return wp_dequeue_style($handle);
   }
 
-  function wpEncodeEmoji($content) {
+  public function wpEncodeEmoji($content) {
     return wp_encode_emoji($content);
   }
 
-  function wpEnqueueMedia(array $args = []) {
+  public function wpEnqueueMedia(array $args = []) {
     return wp_enqueue_media($args);
   }
 
-  function wpEnqueueScript($handle, $src = '', array $deps = [], $ver = false, $in_footer = false) {
+  public function wpEnqueueScript($handle, $src = '', array $deps = [], $ver = false, $in_footer = false) {
     return wp_enqueue_script($handle, $src, $deps, $ver, $in_footer);
   }
 
-  function wpEnqueueStyle($handle, $src = '', array $deps = [], $ver = false, $media = 'all') {
+  public function wpEnqueueStyle($handle, $src = '', array $deps = [], $ver = false, $media = 'all') {
     return wp_enqueue_style($handle, $src, $deps, $ver, $media);
   }
 
-  function wpGetAttachmentImageSrc($attachment_id, $size = 'thumbnail', $icon = false) {
+  public function wpGetAttachmentImageSrc($attachment_id, $size = 'thumbnail', $icon = false) {
     return wp_get_attachment_image_src($attachment_id, $size, $icon);
   }
 
-  function wpGetCurrentUser() {
+  public function wpGetCurrentUser() {
     return wp_get_current_user();
   }
 
-  function wpGetPostTerms($post_id, $taxonomy = 'post_tag', array $args = []) {
+  public function wpGetPostTerms($post_id, $taxonomy = 'post_tag', array $args = []) {
     return wp_get_post_terms($post_id, $taxonomy, $args);
   }
 
-  function wpGetReferer() {
+  public function wpGetReferer() {
     return wp_get_referer();
   }
 
-  function wpGetTheme($stylesheet = null, $theme_root = null) {
+  public function wpGetTheme($stylesheet = null, $theme_root = null) {
     return wp_get_theme($stylesheet, $theme_root);
   }
 
-  function wpInsertPost(array $postarr, $wp_error = false) {
+  public function wpInsertPost(array $postarr, $wp_error = false) {
     return wp_insert_post($postarr, $wp_error);
   }
 
-  function wpJsonEncode($data, $options = 0, $depth = 512) {
+  public function wpJsonEncode($data, $options = 0, $depth = 512) {
     return wp_json_encode($data, $options, $depth);
   }
 
-  function wpLocalizeScript($handle, $object_name, array $l10n) {
+  public function wpLocalizeScript($handle, $object_name, array $l10n) {
     return wp_localize_script($handle, $object_name, $l10n);
   }
 
-  function wpLoginUrl($redirect = '', $force_reauth = false) {
+  public function wpLoginUrl($redirect = '', $force_reauth = false) {
     return wp_login_url($redirect, $force_reauth);
   }
 
-  function wpParseArgs($args, $defaults = '') {
+  public function wpParseArgs($args, $defaults = '') {
     return wp_parse_args($args, $defaults);
   }
 
-  function wpParseUrl($url, $component = -1) {
+  public function wpParseUrl($url, $component = -1) {
     return wp_parse_url($url, $component);
   }
 
-  function wpSpecialcharsDecode($string, $quote_style = ENT_NOQUOTES ) {
+  public function wpSpecialcharsDecode($string, $quote_style = ENT_NOQUOTES ) {
     return wp_specialchars_decode($string, $quote_style);
   }
 
-  function wpPrintScripts($handles = false) {
+  public function wpPrintScripts($handles = false) {
     return wp_print_scripts($handles);
   }
 
-  function wpRemoteGet($url, array $args = []) {
+  public function wpRemoteGet($url, array $args = []) {
     return wp_remote_get($url, $args);
   }
 
-  function wpRemotePost($url, array $args = []) {
+  public function wpRemotePost($url, array $args = []) {
     return wp_remote_post($url, $args);
   }
 
-  function wpRemoteRetrieveBody($response) {
+  public function wpRemoteRetrieveBody($response) {
     return wp_remote_retrieve_body($response);
   }
 
-  function wpRemoteRetrieveResponseCode($response) {
+  public function wpRemoteRetrieveResponseCode($response) {
     return wp_remote_retrieve_response_code($response);
   }
 
-  function wpRemoteRetrieveResponseMessage($response) {
+  public function wpRemoteRetrieveResponseMessage($response) {
     return wp_remote_retrieve_response_message($response);
   }
 
-  function wpSafeRedirect($location, $status = 302) {
+  public function wpSafeRedirect($location, $status = 302) {
     return wp_safe_redirect($location, $status);
   }
 
-  function wpSetCurrentUser($id, $name = '') {
+  public function wpSetCurrentUser($id, $name = '') {
     return wp_set_current_user($id, $name);
   }
 
-  function wpStaticizeEmoji($text) {
+  public function wpStaticizeEmoji($text) {
     return wp_staticize_emoji($text);
   }
 
-  function wpTrimWords($text, $num_words = 55, $more = null) {
+  public function wpTrimWords($text, $num_words = 55, $more = null) {
     return wp_trim_words($text, $num_words, $more);
   }
 
-  function wpUploadDir($time = null, $create_dir = true, $refresh_cache = false) {
+  public function wpUploadDir($time = null, $create_dir = true, $refresh_cache = false) {
     return wp_upload_dir($time, $create_dir, $refresh_cache);
   }
 
-  function wpVerifyNonce($nonce, $action = -1) {
+  public function wpVerifyNonce($nonce, $action = -1) {
     return wp_verify_nonce($nonce, $action);
   }
 
-  function wpautop($pee, $br = true) {
+  public function wpautop($pee, $br = true) {
     return wpautop($pee, $br);
   }
 
@@ -566,7 +566,7 @@ class Functions {
    * @param string $host
    * @return array|bool
    */
-  function parseDbHost($host) {
+  public function parseDbHost($host) {
     global $wpdb;
     if (method_exists($wpdb, 'parse_db_host')) {
       return $wpdb->parse_db_host($host);
diff --git a/lib/WP/Notice.php b/lib/WP/Notice.php
index 97c68ea688..4d2682366f 100644
--- a/lib/WP/Notice.php
+++ b/lib/WP/Notice.php
@@ -17,7 +17,7 @@ class Notice {
   private $data_notice_name;
   private $render_in_paragraph;
 
-  function __construct($type, $message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
+  public function __construct($type, $message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
     $this->type = $type;
     $this->message = $message;
     $this->classes = $classes;
@@ -25,11 +25,11 @@ class Notice {
     $this->render_in_paragraph = $render_in_paragraph;
   }
 
-  function getMessage() {
+  public function getMessage() {
     return $this->message;
   }
 
-  static function displayError($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true, $show_error_title = true) {
+  public static function displayError($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true, $show_error_title = true) {
     if ($show_error_title) {
       $message = sprintf(
         "<b>%s </b> %s",
@@ -40,15 +40,15 @@ class Notice {
     self::createNotice(self::TYPE_ERROR, $message, $classes, $data_notice_name, $render_in_paragraph);
   }
 
-  static function displayWarning($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
+  public static function displayWarning($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
     return self::createNotice(self::TYPE_WARNING, $message, $classes, $data_notice_name, $render_in_paragraph);
   }
 
-  static function displaySuccess($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
+  public static function displaySuccess($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
     self::createNotice(self::TYPE_SUCCESS, $message, $classes, $data_notice_name, $render_in_paragraph);
   }
 
-  static function displayInfo($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
+  public static function displayInfo($message, $classes = '', $data_notice_name = '', $render_in_paragraph = true) {
     self::createNotice(self::TYPE_INFO, $message, $classes, $data_notice_name, $render_in_paragraph);
   }
 
@@ -58,7 +58,7 @@ class Notice {
     return $notice;
   }
 
-  function displayWPNotice() {
+  public function displayWPNotice() {
     $class = sprintf('notice notice-%s mailpoet_notice_server %s', $this->type, $this->classes);
     $message = nl2br($this->message);
     $data_notice_name = !empty($this->data_notice_name) ? sprintf('data-notice="%s"', $this->data_notice_name) : '';
diff --git a/lib/WP/Posts.php b/lib/WP/Posts.php
index cc34c1c932..ce57d4c336 100644
--- a/lib/WP/Posts.php
+++ b/lib/WP/Posts.php
@@ -6,7 +6,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class Posts {
 
-  static function getTerms($args) {
+  public static function getTerms($args) {
     // Since WordPress 4.5.0 signature of get_terms changed to require
     // one argument array, where taxonomy is key of that array
     if (version_compare(WPFunctions::get()->getBloginfo('version'), '4.5.0', '>=')) {
@@ -18,7 +18,7 @@ class Posts {
     }
   }
 
-  static function getTypes($args = [], $output = 'names', $operator = 'and') {
+  public static function getTypes($args = [], $output = 'names', $operator = 'and') {
     $defaults = [
       'exclude_from_search' => false,
     ];
diff --git a/lib/WP/Readme.php b/lib/WP/Readme.php
index 34ca67e6c6..2f9ba68d9b 100644
--- a/lib/WP/Readme.php
+++ b/lib/WP/Readme.php
@@ -3,7 +3,7 @@
 namespace MailPoet\WP;
 
 class Readme {
-  static function parseChangelog($readme_txt, $limit = null) {
+  public static function parseChangelog($readme_txt, $limit = null) {
     // Extract changelog section of the readme.txt
     preg_match('/== Changelog ==(.*?)(\n==|$)/is', $readme_txt, $changelog);
 
diff --git a/lib/WooCommerce/Helper.php b/lib/WooCommerce/Helper.php
index 32b318c8b6..3cf9bfa1dd 100644
--- a/lib/WooCommerce/Helper.php
+++ b/lib/WooCommerce/Helper.php
@@ -4,47 +4,47 @@ namespace MailPoet\WooCommerce;
 
 class Helper {
 
-  function isWooCommerceActive() {
+  public function isWooCommerceActive() {
     return class_exists('WooCommerce');
   }
 
-  function WC() {
+  public function WC() {
     return WC();
   }
 
-  function wcGetCustomerOrderCount($user_id) {
+  public function wcGetCustomerOrderCount($user_id) {
     return wc_get_customer_order_count($user_id);
   }
 
-  function wcGetOrder($order = false) {
+  public function wcGetOrder($order = false) {
     return wc_get_order($order);
   }
 
-  function wcGetOrders(array $args) {
+  public function wcGetOrders(array $args) {
     return wc_get_orders($args);
   }
 
-  function wcPrice($price, array $args = []) {
+  public function wcPrice($price, array $args = []) {
     return wc_price($price, $args);
   }
 
-  function wcGetProduct($the_product = false) {
+  public function wcGetProduct($the_product = false) {
     return wc_get_product($the_product);
   }
 
-  function getWoocommerceCurrency() {
+  public function getWoocommerceCurrency() {
     return get_woocommerce_currency();
   }
 
-  function wcLightOrDark($color, $dark, $light) {
+  public function wcLightOrDark($color, $dark, $light) {
     return wc_light_or_dark($color, $dark, $light);
   }
 
-  function wcHexIsLight($color) {
+  public function wcHexIsLight($color) {
     return wc_hex_is_light($color);
   }
 
-  function getOrdersCountCreatedBefore($date_time) {
+  public function getOrdersCountCreatedBefore($date_time) {
     global $wpdb;
     $result = $wpdb->get_var( "
         SELECT DISTINCT count(p.ID) FROM {$wpdb->prefix}posts as p
@@ -53,7 +53,7 @@ class Helper {
     return (int)$result;
   }
 
-  function getRawPrice($price, array $args = []) {
+  public function getRawPrice($price, array $args = []) {
     $html_price = $this->wcPrice($price, $args);
     return html_entity_decode(strip_tags($html_price));
   }
diff --git a/lib/WooCommerce/Settings.php b/lib/WooCommerce/Settings.php
index c238442cec..7f597672f8 100644
--- a/lib/WooCommerce/Settings.php
+++ b/lib/WooCommerce/Settings.php
@@ -14,7 +14,7 @@ class Settings {
   /** @var SettingsController */
   private $settings;
 
-  function __construct(
+  public function __construct(
     Renderer $renderer,
     SettingsController $settings
   ) {
@@ -22,7 +22,7 @@ class Settings {
     $this->settings = $settings;
   }
 
-  function disableWooCommerceSettings() {
+  public function disableWooCommerceSettings() {
     if (
       !isset($_GET['tab'])
       || $_GET['tab'] !== 'email'
diff --git a/lib/WooCommerce/Subscription.php b/lib/WooCommerce/Subscription.php
index 4447956dc0..0f6c211a4e 100644
--- a/lib/WooCommerce/Subscription.php
+++ b/lib/WooCommerce/Subscription.php
@@ -21,7 +21,7 @@ class Subscription {
   /** @var WPFunctions */
   private $wp;
 
-  function __construct(
+  public function __construct(
     SettingsController $settings,
     WPFunctions $wp
   ) {
@@ -29,7 +29,7 @@ class Subscription {
     $this->wp = $wp;
   }
 
-  function extendWooCommerceCheckoutForm() {
+  public function extendWooCommerceCheckoutForm() {
     $input_name = self::CHECKOUT_OPTIN_INPUT_NAME;
     $checked = $this->isCurrentUserSubscribed();
     if (!empty($_POST[self::CHECKOUT_OPTIN_INPUT_NAME])) {
@@ -67,7 +67,7 @@ class Subscription {
       && $subscriber_segment->status === Subscriber::STATUS_SUBSCRIBED;
   }
 
-  function subscribeOnCheckout($order_id, $data) {
+  public function subscribeOnCheckout($order_id, $data) {
     if (empty($data['billing_email'])) {
       // no email in posted order data
       return null;
diff --git a/lib/WooCommerce/TransactionalEmails.php b/lib/WooCommerce/TransactionalEmails.php
index 10a2d8ed07..5026fa2a28 100644
--- a/lib/WooCommerce/TransactionalEmails.php
+++ b/lib/WooCommerce/TransactionalEmails.php
@@ -35,7 +35,7 @@ class TransactionalEmails {
   /** @var NewslettersRepository */
   private $newsletters_repository;
 
-  function __construct(WPFunctions $wp, SettingsController $settings, Template $template, Renderer $renderer, Helper $woocommerce_helper, NewslettersRepository $newsletters_repository) {
+  public function __construct(WPFunctions $wp, SettingsController $settings, Template $template, Renderer $renderer, Helper $woocommerce_helper, NewslettersRepository $newsletters_repository) {
     $this->wp = $wp;
     $this->settings = $settings;
     $this->template = $template;
diff --git a/lib/WooCommerce/TransactionalEmails/Renderer.php b/lib/WooCommerce/TransactionalEmails/Renderer.php
index 5afc71f29c..ac26251216 100644
--- a/lib/WooCommerce/TransactionalEmails/Renderer.php
+++ b/lib/WooCommerce/TransactionalEmails/Renderer.php
@@ -20,7 +20,7 @@ class Renderer {
   /** @var string */
   private $html_after_content;
 
-  function __construct(csstidy $css_parser) {
+  public function __construct(csstidy $css_parser) {
     $this->css_parser = $css_parser;
     $this->html_before_content = '';
     $this->html_after_content = '';
diff --git a/tasks/phpstan/PremiumContainerConfigurator.php b/tasks/phpstan/PremiumContainerConfigurator.php
index 52a5e7a503..78a3e30696 100644
--- a/tasks/phpstan/PremiumContainerConfigurator.php
+++ b/tasks/phpstan/PremiumContainerConfigurator.php
@@ -7,12 +7,12 @@ use MailPoetVendor\Symfony\Component\DependencyInjection\ContainerBuilder;
 
 // phpcs:ignore Squiz.Classes.ClassFileName
 class ContainerConfigurator implements IContainerConfigurator {
-  function configure(ContainerBuilder $container) {
+  public function configure(ContainerBuilder $container) {
   }
 
-  function getDumpNamespace() {
+  public function getDumpNamespace() {
   }
 
-  function getDumpClassname() {
+  public function getDumpClassname() {
   }
 }
diff --git a/tasks/phpstan/woocommerce.php b/tasks/phpstan/woocommerce.php
index 62ebacc956..42131e7f09 100644
--- a/tasks/phpstan/woocommerce.php
+++ b/tasks/phpstan/woocommerce.php
@@ -2,7 +2,7 @@
 
 // phpcs:ignore
 class WooCommerce {
-  function mailer() {
+  public function mailer() {
   }
 }
 
diff --git a/tasks/release/ChangelogController.php b/tasks/release/ChangelogController.php
index 811a6b9a51..545cf378d4 100644
--- a/tasks/release/ChangelogController.php
+++ b/tasks/release/ChangelogController.php
@@ -13,18 +13,18 @@ class ChangelogController {
   /** @var JiraController */
   private $jira;
 
-  function __construct(JiraController $jira, $readme_file) {
+  public function __construct(JiraController $jira, $readme_file) {
     $this->jira = $jira;
     $this->readme_file = $readme_file;
   }
 
-  function update($version_name = null) {
+  public function update($version_name = null) {
     $changelog_data = $this->get($version_name);
     $this->updateReadme($changelog_data[0], $changelog_data[1]);
     return $changelog_data;
   }
 
-  function get($version_name = null) {
+  public function get($version_name = null) {
     $version = $this->jira->getVersion($version_name);
     $issues = $this->jira->getIssuesDataForVersion($version);
     $heading = $this->renderHeading($version);
diff --git a/tasks/release/JiraController.php b/tasks/release/JiraController.php
index 4d6aa1157d..ddf1cccb52 100644
--- a/tasks/release/JiraController.php
+++ b/tasks/release/JiraController.php
@@ -47,7 +47,7 @@ class JiraController {
   /**
    * @see https://developer.atlassian.com/cloud/jira/platform/rest/v3/#api-api-3-project-projectIdOrKey-versions-get
    */
-  function getVersion($version_name = null) {
+  public function getVersion($version_name = null) {
     $response = $this->http_client->get("project/$this->project/versions");
     $versions = json_decode($response->getBody()->getContents(), true);
     if ($version_name === null) {
@@ -61,7 +61,7 @@ class JiraController {
     throw new \Exception('Unknown project version');
   }
 
-  function getLastVersion() {
+  public function getLastVersion() {
     $response = $this->http_client->get("project/$this->project/version", [
       'query' => [
         'maxResults' => 1,
@@ -75,7 +75,7 @@ class JiraController {
     return reset($version['values']);
   }
 
-  function getLastReleasedVersion() {
+  public function getLastReleasedVersion() {
     $response = $this->http_client->get("project/$this->project/version", [
       'query' => [
         'maxResults' => 1,
@@ -93,7 +93,7 @@ class JiraController {
   /**
    * @see https://developer.atlassian.com/cloud/jira/platform/rest/v3/#api-api-3-version-post
    */
-  function createVersion($version_name) {
+  public function createVersion($version_name) {
     $data = [
       'name' => $version_name,
       'archived' => false,
@@ -105,7 +105,7 @@ class JiraController {
     return json_decode($response->getBody()->getContents(), true);
   }
 
-  function releaseVersion($version_name) {
+  public function releaseVersion($version_name) {
     $version = $this->getVersion($version_name);
     $response = $this->http_client->put("version/$version[id]", [
       'json' => [
@@ -116,7 +116,7 @@ class JiraController {
     return json_decode($response->getBody()->getContents(), true);
   }
 
-  function getIssuesDataForVersion($version) {
+  public function getIssuesDataForVersion($version) {
     $changelog_id = self::CHANGELOG_FIELD_ID;
     $release_note_id = self::RELEASENOTE_FIELD_ID;
     $pull_requests_id = self::PULL_REQUESTS_ID;
@@ -136,7 +136,7 @@ class JiraController {
   /**
    * @see https://developer.atlassian.com/cloud/jira/platform/rest/v3/#api-api-3-search-get
    */
-  function search($jql, array $fields = null) {
+  public function search($jql, array $fields = null) {
     $params = ['jql' => $jql];
     if ($fields) {
       $params['fields'] = join(',', $fields);
@@ -148,7 +148,7 @@ class JiraController {
   /**
    * @see https://developer.atlassian.com/cloud/jira/platform/rest/v3/#api-api-3-issue-issueIdOrKey-put
    */
-  function updateIssue($key, $data) {
+  public function updateIssue($key, $data) {
     $this->http_client->put("issue/$key", ['json' => $data]);
   }
 }
diff --git a/tasks/release/ReleaseVersionController.php b/tasks/release/ReleaseVersionController.php
index 1baf16464a..86f357e3cb 100644
--- a/tasks/release/ReleaseVersionController.php
+++ b/tasks/release/ReleaseVersionController.php
@@ -10,12 +10,12 @@ class ReleaseVersionController {
   /** @var string */
   private $project;
 
-  function __construct(JiraController $jira, $project) {
+  public function __construct(JiraController $jira, $project) {
     $this->jira = $jira;
     $this->project = $project;
   }
 
-  function assignVersionToCompletedTickets($version = null) {
+  public function assignVersionToCompletedTickets($version = null) {
     $version = $this->ensureCorrectVersion($version);
     if (!$version) {
       throw new \Exception('The version is invalid or already released');
@@ -32,7 +32,7 @@ class ReleaseVersionController {
     return [$version, join("\n", $output)];
   }
 
-  function determineNextVersion() {
+  public function determineNextVersion() {
     $last_version = $this->jira->getLastReleasedVersion();
 
     $part_to_increment = VersionHelper::PATCH;
diff --git a/tasks/release/VersionHelper.php b/tasks/release/VersionHelper.php
index 717ddb4cca..ea3b1d44f5 100644
--- a/tasks/release/VersionHelper.php
+++ b/tasks/release/VersionHelper.php
@@ -9,7 +9,7 @@ class VersionHelper {
   const MINOR = 'Minor';
   const PATCH = 'Patch';
 
-  static function incrementVersion($version, $part_to_increment = self::PATCH) {
+  public static function incrementVersion($version, $part_to_increment = self::PATCH) {
     $parsed_version = is_array($version) ? $version : self::parseVersion($version);
 
     switch ($part_to_increment) {
@@ -26,7 +26,7 @@ class VersionHelper {
     return is_array($version) ? $parsed_version : self::buildVersion($parsed_version);
   }
 
-  static function parseVersion($version) {
+  public static function parseVersion($version) {
     if (!preg_match(self::VERSION_REGEXP, $version, $matches)) {
       throw new \Exception('Incorrect version format');
     }
@@ -37,15 +37,15 @@ class VersionHelper {
     ];
   }
 
-  static function buildVersion(array $parts) {
+  public static function buildVersion(array $parts) {
     return sprintf('%d.%d.%d', $parts[self::MAJOR], $parts[self::MINOR], $parts[self::PATCH]);
   }
 
-  static function buildMinorVersion(array $parts) {
+  public static function buildMinorVersion(array $parts) {
     return sprintf('%d.%d', $parts[self::MAJOR], $parts[self::MINOR]);
   }
 
-  static function validateVersion($version) {
+  public static function validateVersion($version) {
     return preg_match(self::VERSION_REGEXP, $version);
   }
 }
diff --git a/tests/DataFactories/Features.php b/tests/DataFactories/Features.php
index 3134f12ea3..2013ad84ae 100644
--- a/tests/DataFactories/Features.php
+++ b/tests/DataFactories/Features.php
@@ -10,11 +10,11 @@ class Features {
   /** @var FeatureFlagsRepository */
   private $flags;
 
-  function __construct() {
+  public function __construct() {
     $this->flags = ContainerWrapper::getInstance(WP_DEBUG)->get(FeatureFlagsRepository::class);
   }
 
-  function withFeatureEnabled($name) {
+  public function withFeatureEnabled($name) {
     $this->flags->createOrUpdate([
       'name' => $name,
       'value' => true,
@@ -22,7 +22,7 @@ class Features {
     return $this;
   }
 
-  function withFeatureDisabled($name) {
+  public function withFeatureDisabled($name) {
     $this->flags->createOrUpdate([
       'name' => $name,
       'value' => false,
diff --git a/tests/DataFactories/ScheduledTask.php b/tests/DataFactories/ScheduledTask.php
index 4dd34901cd..4f7066a5fa 100644
--- a/tests/DataFactories/ScheduledTask.php
+++ b/tests/DataFactories/ScheduledTask.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\DataFactories;
 
 class ScheduledTask {
-  function deleteAll() {
+  public function deleteAll() {
     $tasks = \MailPoet\Models\ScheduledTask::findMany();
     foreach ($tasks as $task) {
       $task->delete();
diff --git a/tests/DataFactories/Settings.php b/tests/DataFactories/Settings.php
index 73a0508956..e409fed8a5 100644
--- a/tests/DataFactories/Settings.php
+++ b/tests/DataFactories/Settings.php
@@ -14,7 +14,7 @@ class Settings {
     $this->settings->resetCache();
   }
 
-  function withDefaultSettings() {
+  public function withDefaultSettings() {
     $this->withCronTriggerMethod('Linux Cron');
     $this->withSendingMethodSmtpMailhog();
     $this->withSender('admin', 'wp@example.com');
@@ -23,23 +23,23 @@ class Settings {
     $this->withEmailNotificationsDisabled();
   }
 
-  function withCronTriggerMethod($method) {
+  public function withCronTriggerMethod($method) {
     $this->settings->set('cron_trigger.method', $method);
     return $this;
   }
 
-  function withSender($name, $address) {
+  public function withSender($name, $address) {
     $this->settings->set('sender.name', $name);
     $this->settings->set('sender.address', $address);
   }
 
-  function withEmailNotificationsDisabled() {
+  public function withEmailNotificationsDisabled() {
     $this->settings->set('stats_notifications.enabled', 0);
     $this->settings->set('subscriber_email_notification.enabled', 0);
     return $this;
   }
 
-  function withConfirmationEmailSubject($subject = null) {
+  public function withConfirmationEmailSubject($subject = null) {
     if ($subject === null) {
       $subject = sprintf('Confirm your subscription to %1$s', get_option('blogname'));
     }
@@ -47,7 +47,7 @@ class Settings {
     return $this;
   }
 
-  function withConfirmationEmailBody($body = null) {
+  public function withConfirmationEmailBody($body = null) {
     if ($body === null) {
       $body = "Hello,\n\nWelcome to our newsletter!\n\nPlease confirm your subscription to our list by clicking the link below: \n\n[activation_link]I confirm my subscription![/activation_link]\n\nThank you,\n\nThe Team";
     }
@@ -55,44 +55,44 @@ class Settings {
     return $this;
   }
 
-  function withConfirmationEmailEnabled() {
+  public function withConfirmationEmailEnabled() {
     $this->settings->set('signup_confirmation.enabled', '1');
     return $this;
   }
 
-  function withConfirmationEmailDisabled() {
+  public function withConfirmationEmailDisabled() {
     $this->settings->set('signup_confirmation.enabled', '');
     return $this;
   }
 
-  function withTrackingDisabled() {
+  public function withTrackingDisabled() {
     $this->settings->set('tracking.enabled', false);
     return $this;
   }
 
-  function withTrackingEnabled() {
+  public function withTrackingEnabled() {
     $this->settings->set('tracking.enabled', true);
     return $this;
   }
 
-  function withTodayInstallationDate() {
+  public function withTodayInstallationDate() {
     $this->settings->set('installed_at', date("Y-m-d H:i:s"));
   }
 
-  function withSkippedTutorials() {
+  public function withSkippedTutorials() {
     $this->settings->set('show_intro', 0);
     $this->settings->set('display_nps_poll', 0);
     $this->settings->set('show_congratulate_after_first_newsletter', 0);
     return $this;
   }
 
-  function withSendingMethod($sending_method) {
+  public function withSendingMethod($sending_method) {
     $this->settings->set('mta.method', $sending_method);
     $this->settings->set('mta_group', $sending_method === Mailer::METHOD_SMTP ? 'smtp' : 'website');
     return $this;
   }
 
-  function withSendingMethodMailPoet() {
+  public function withSendingMethodMailPoet() {
     $mailPoetSendingKey = getenv('WP_TEST_MAILER_MAILPOET_API');
     $this->settings->set('mta_group', 'mailpoet');
     $this->settings->set('mta.method', 'MailPoet');
@@ -102,7 +102,7 @@ class Settings {
     return $this;
   }
 
-  function withSendingMethodSmtpMailhog() {
+  public function withSendingMethodSmtpMailhog() {
     $this->settings->set('mta_group', 'smtp');
     $this->settings->set('mta.method', Mailer::METHOD_SMTP);
     $this->settings->set('mta.port', 1025);
@@ -116,68 +116,68 @@ class Settings {
     $this->settings->set('smtp_provider', 'manual');
   }
 
-  function withSendingError($error_message, $operation = 'send') {
+  public function withSendingError($error_message, $operation = 'send') {
     $this->settings->set('mta_log.status', 'paused');
     $this->settings->set('mta_log.error.operation', $operation);
     $this->settings->set('mta_log.error.error_message', $error_message);
     return $this;
   }
 
-  function withCookieRevenueTracking() {
+  public function withCookieRevenueTracking() {
     $this->settings->set('woocommerce.accept_cookie_revenue_tracking.enabled', "1");
     $this->settings->set('woocommerce.accept_cookie_revenue_tracking.set', "1");
     return $this;
   }
 
-  function withCookieRevenueTrackingDisabled() {
+  public function withCookieRevenueTrackingDisabled() {
     $this->settings->set('woocommerce.accept_cookie_revenue_tracking.enabled', "0");
     $this->settings->set('woocommerce.accept_cookie_revenue_tracking.set', "1");
     return $this;
   }
 
-  function withWooCommerceListImportPageDisplayed($was_shown) {
+  public function withWooCommerceListImportPageDisplayed($was_shown) {
     $this->settings->set('woocommerce_import_screen_displayed', $was_shown ? 1 : 0);
     return $this;
   }
 
-  function withWooCommerceCheckoutOptinEnabled() {
+  public function withWooCommerceCheckoutOptinEnabled() {
     $this->settings->set('woocommerce.optin_on_checkout.enabled', true);
     $this->settings->set('woocommerce.optin_on_checkout.message', 'Yes, I would like to be added to your mailing list');
     return $this;
   }
 
-  function withWooCommerceCheckoutOptinDisabled() {
+  public function withWooCommerceCheckoutOptinDisabled() {
     $this->settings->set('woocommerce.optin_on_checkout.enabled', false);
     $this->settings->set('woocommerce.optin_on_checkout.message', '');
     return $this;
   }
 
-  function withWooCommerceEmailCustomizerEnabled() {
+  public function withWooCommerceEmailCustomizerEnabled() {
     $this->settings->set('woocommerce.use_mailpoet_editor', true);
     return $this;
   }
 
-  function withWooCommerceEmailCustomizerDisabled() {
+  public function withWooCommerceEmailCustomizerDisabled() {
     $this->settings->set('woocommerce.use_mailpoet_editor', false);
     return $this;
   }
 
-  function withDeactivateSubscriberAfter3Months() {
+  public function withDeactivateSubscriberAfter3Months() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 90);
     return $this;
   }
 
-  function withDeactivateSubscriberAfter6Months() {
+  public function withDeactivateSubscriberAfter6Months() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 180);
     return $this;
   }
 
-  function withCaptchaType($type = null) {
+  public function withCaptchaType($type = null) {
     $this->settings->set('captcha.type', $type);
     return $this;
   }
 
-  function withInstalledAt(\DateTime $date) {
+  public function withInstalledAt(\DateTime $date) {
     $this->settings->set('installed_at', $date);
     return $this;
   }
diff --git a/tests/DataFactories/UserFlags.php b/tests/DataFactories/UserFlags.php
index e8e5c6a527..2434802c1c 100644
--- a/tests/DataFactories/UserFlags.php
+++ b/tests/DataFactories/UserFlags.php
@@ -13,21 +13,21 @@ class UserFlags {
   /** @var UserFlagsRepository */
   private $user_flags_repository;
 
-  function __construct($user_id) {
+  public function __construct($user_id) {
     $this->user_id = $user_id;
     $this->user_flags_repository = ContainerWrapper::getInstance()->get(UserFlagsRepository::class);
   }
 
-  function withDefaultFlags() {
+  public function withDefaultFlags() {
     $this->withEditorTutorialSeen();
   }
 
-  function withEditorTutorialSeen() {
+  public function withEditorTutorialSeen() {
     $this->withFlag('editor_tutorial_seen', 1);
     return $this;
   }
 
-  function withFlag($name, $value) {
+  public function withFlag($name, $value) {
     $user_flag = $this->user_flags_repository->findOneBy([
       'user_id' => $this->user_id,
       'name' => $name,
diff --git a/tests/DataFactories/WooCommerceCustomer.php b/tests/DataFactories/WooCommerceCustomer.php
index e12997edaf..c855edd5c5 100644
--- a/tests/DataFactories/WooCommerceCustomer.php
+++ b/tests/DataFactories/WooCommerceCustomer.php
@@ -10,7 +10,7 @@ class WooCommerceCustomer {
   /** @var array */
   private $data;
 
-  function __construct(\AcceptanceTester $tester) {
+  public function __construct(\AcceptanceTester $tester) {
     $unique_id = bin2hex(random_bytes(7)); // phpcs:ignore
     $this->tester = $tester;
     $this->data = [
@@ -25,7 +25,7 @@ class WooCommerceCustomer {
  * @param string $name
  * @return $this
  */
-  function withFirstName($name) {
+  public function withFirstName($name) {
     return $this->update('first_name', $name);
   }
 
@@ -33,7 +33,7 @@ class WooCommerceCustomer {
    * @param string $name
    * @return $this
    */
-  function withLastName($name) {
+  public function withLastName($name) {
     return $this->update('last_name', $name);
   }
 
@@ -41,7 +41,7 @@ class WooCommerceCustomer {
    * @param string $password
    * @return $this
    */
-  function withPassword($password) {
+  public function withPassword($password) {
     return $this->update('password', $password);
   }
 
@@ -49,12 +49,12 @@ class WooCommerceCustomer {
    * @param string $email
    * @return $this
    */
-  function withEmail($email) {
+  public function withEmail($email) {
     return $this->update('email', $email);
   }
 
 
-  function create() {
+  public function create() {
     $create_output = $this->tester->cliToArray(['wc', 'customer', 'create', '--porcelain', '--user=admin', "--first_name={$this->data['first_name']}", "--last_name={$this->data['last_name']}", "--email={$this->data['email']}", "--password={$this->data['password']}"]);
     $customer_out = $this->tester->cliToArray(['wc', 'customer', 'get', $create_output[0], '--format=json', '--user=admin']);
     return json_decode($customer_out[0], true);
@@ -63,11 +63,11 @@ class WooCommerceCustomer {
   /**
    * @param int $id
    */
-  function delete($id) {
+  public function delete($id) {
     $this->tester->cliToArray(['wc', 'customer', 'delete', $id, '--force=1', '--user=admin']);
   }
 
-  function deleteAll() {
+  public function deleteAll() {
     $list = $this->tester->cliToArray(['wc', 'customer', 'list', '--format=json', '--user=admin', '--fields=id']);
     foreach (json_decode($list[0], true) as $item) {
       $this->delete($item['id']);
diff --git a/tests/DataFactories/WooCommerceOrder.php b/tests/DataFactories/WooCommerceOrder.php
index 10edd876cf..fd8f1bb21c 100644
--- a/tests/DataFactories/WooCommerceOrder.php
+++ b/tests/DataFactories/WooCommerceOrder.php
@@ -19,7 +19,7 @@ class WooCommerceOrder {
   const STATUS_COMPLETED = 'completed';
   const STATUS_REFUNDED = 'refunded';
 
-  function __construct(\AcceptanceTester $tester) {
+  public function __construct(\AcceptanceTester $tester) {
     $unique_id = bin2hex(random_bytes(7)); // phpcs:ignore
     $this->tester = $tester;
     $this->data = [
@@ -38,11 +38,11 @@ class WooCommerceOrder {
     ];
   }
 
-  function withStatus($status) {
+  public function withStatus($status) {
     return $this->update(['status' => $status]);
   }
 
-  function withDateCreated($date) {
+  public function withDateCreated($date) {
     return $this->update(['date_created' => $date]);
   }
 
@@ -50,7 +50,7 @@ class WooCommerceOrder {
    * @param array $customer_data Customer created via WooCommerceCustomer factory
    * @return $this
    */
-  function withCustomer($customer_data) {
+  public function withCustomer($customer_data) {
     $billing = $this->data['billing'];
     $billing['first_name'] = $customer_data['first_name'];
     $billing['last_name'] = $customer_data['last_name'];
@@ -58,7 +58,7 @@ class WooCommerceOrder {
     return $this->update(['customer_id' => $customer_data['id'], 'billing' => $billing]);
   }
 
-  function withCurrency($currency) {
+  public function withCurrency($currency) {
     return $this->update(['currency' => $currency]);
   }
 
@@ -67,7 +67,7 @@ class WooCommerceOrder {
    * @param int[] $quantities
    * @return $this
    */
-  function withProducts($products, $quantities = null) {
+  public function withProducts($products, $quantities = null) {
     $products_data = [];
     foreach ($products as $key => $product) {
       $products_data[] = [
@@ -81,7 +81,7 @@ class WooCommerceOrder {
   }
 
 
-  function create() {
+  public function create() {
     $cmd = ['wc', 'shop_order', 'create', '--porcelain', '--user=admin'];
     $cmd[] = '--status=' . $this->data['status'];
     $cmd[] = '--customer_id=' . $this->data['customer_id'];
@@ -106,11 +106,11 @@ class WooCommerceOrder {
   /**
    * @param int $id
    */
-  function delete($id) {
+  public function delete($id) {
     $this->tester->cliToArray(['wc', 'shop_order', 'delete', $id, '--force=1', '--user=admin']);
   }
 
-  function deleteAll() {
+  public function deleteAll() {
     $list = $this->tester->cliToArray(['wc', 'shop_order', 'list', '--format=json', '--user=admin', '--fields=id']);
     foreach (json_decode($list[0], true) as $item) {
       $this->delete($item['id']);
diff --git a/tests/DataFactories/WooCommerceProduct.php b/tests/DataFactories/WooCommerceProduct.php
index baa0748977..2ec532fc0c 100644
--- a/tests/DataFactories/WooCommerceProduct.php
+++ b/tests/DataFactories/WooCommerceProduct.php
@@ -16,7 +16,7 @@ class WooCommerceProduct {
   const TYPE_EXTERNAL = 'external';
   const TYPE_VARIABLE = 'variable';
 
-  function __construct(\AcceptanceTester $tester) {
+  public function __construct(\AcceptanceTester $tester) {
     $this->tester = $tester;
     $this->data = [
       'name' => 'Product',
@@ -35,7 +35,7 @@ class WooCommerceProduct {
    * @param string $name
    * @return $this
    */
-  function withName($name) {
+  public function withName($name) {
     return $this->update('name', $name);
   }
 
@@ -43,7 +43,7 @@ class WooCommerceProduct {
    * @param string $description
    * @return $this
    */
-  function withDescription($description) {
+  public function withDescription($description) {
     return $this->update('description', $description);
   }
 
@@ -51,7 +51,7 @@ class WooCommerceProduct {
    * @param string $shortDescription
    * @return $this
    */
-  function withShortDescription($shortDescription) {
+  public function withShortDescription($shortDescription) {
     return $this->update('shortDescription', $shortDescription);
   }
 
@@ -59,7 +59,7 @@ class WooCommerceProduct {
    * @param string $type
    * @return $this
    */
-  function withType($type) {
+  public function withType($type) {
     return $this->update('type', $type);
   }
 
@@ -67,7 +67,7 @@ class WooCommerceProduct {
    * @param string $sku
    * @return $this
    */
-  function withSku($sku) {
+  public function withSku($sku) {
     return $this->update('sku', $sku);
   }
 
@@ -75,7 +75,7 @@ class WooCommerceProduct {
    * @param int $price
    * @return $this
    */
-  function withPrice($price) {
+  public function withPrice($price) {
     return $this->update('price', $price);
   }
 
@@ -83,7 +83,7 @@ class WooCommerceProduct {
    * @param array $ids
    * @return $this
    */
-  function withCategoryIds($ids) {
+  public function withCategoryIds($ids) {
     $ids = array_map(function($id){
       return ['id' => $id];
     }, $ids);
@@ -94,7 +94,7 @@ class WooCommerceProduct {
    * @param array $ids
    * @return $this
    */
-  function withTagIds($ids) {
+  public function withTagIds($ids) {
     $ids = array_map(function($id){
       return ['id' => $id];
     }, $ids);
@@ -105,14 +105,14 @@ class WooCommerceProduct {
    * @param array $images
    * @return $this
    */
-  function withImages($images) {
+  public function withImages($images) {
     $images = array_map(function($src){
       return ['src' => $src];
     }, $images);
     return $this->update('images', $images);
   }
 
-  function create() {
+  public function create() {
     $create_command = ['wc', 'product', 'create', '--porcelain', '--user=admin'];
     $create_command[] = "--name={$this->data['name']}";
     $create_command[] = "--type={$this->data['type']}";
@@ -142,12 +142,12 @@ class WooCommerceProduct {
     return json_decode($product_out[0], true);
   }
 
-  function createCategory($name) {
+  public function createCategory($name) {
     $create_output = $this->tester->cliToArray(['wc', 'product_cat', 'create', '--porcelain', '--user=admin', "--name=$name"]);
     return $create_output[0];
   }
 
-  function createTag($name) {
+  public function createTag($name) {
     $create_output = $this->tester->cliToArray(['wc', 'product_tag', 'create', '--porcelain', '--user=admin', "--name=$name"]);
     return $create_output[0];
   }
@@ -155,11 +155,11 @@ class WooCommerceProduct {
   /**
    * @param int $id
    */
-  function delete($id) {
+  public function delete($id) {
     $this->tester->cliToArray(['wc', 'product', 'delete', $id, '--force=1', '--user=admin']);
   }
 
-  function deleteAll() {
+  public function deleteAll() {
     $list = $this->tester->cliToArray(['wc', 'product', 'list', '--format=json', '--user=admin', '--fields=id']);
     foreach (json_decode($list[0], true) as $item) {
       $this->delete($item['id']);
diff --git a/tests/DataGenerator/DataGenerator.php b/tests/DataGenerator/DataGenerator.php
index aa3fb3db05..ddcf4bca62 100644
--- a/tests/DataGenerator/DataGenerator.php
+++ b/tests/DataGenerator/DataGenerator.php
@@ -12,11 +12,11 @@ class DataGenerator {
   /** @var Output */
   private $console;
 
-  function __construct(Output $console) {
+  public function __construct(Output $console) {
     $this->console = $console;
   }
 
-  function run($generator_name) {
+  public function run($generator_name) {
     ini_set('memory_limit', '1024M');
     $timer = time();
     try {
diff --git a/tests/DataGenerator/Generators/WooCommercePastRevenues.php b/tests/DataGenerator/Generators/WooCommercePastRevenues.php
index 79b908bb70..a608053e7f 100644
--- a/tests/DataGenerator/Generators/WooCommercePastRevenues.php
+++ b/tests/DataGenerator/Generators/WooCommercePastRevenues.php
@@ -30,7 +30,7 @@ class WooCommercePastRevenues {
   const POST_NOTIFICATIONS_HISTORY = 30;
   const STANDARD_NEWSLETTER = 30;
 
-  function generate() {
+  public function generate() {
     $this->prepareDatabaseTables();
     // Reset hooks to prevent revenues calculation during generating
     remove_all_actions('woocommerce_order_status_completed');
diff --git a/tests/_support/CheckSkippedTestsExtension.php b/tests/_support/CheckSkippedTestsExtension.php
index 57a9237e2b..efa3920f20 100644
--- a/tests/_support/CheckSkippedTestsExtension.php
+++ b/tests/_support/CheckSkippedTestsExtension.php
@@ -9,7 +9,7 @@ class CheckSkippedTestsExtension extends Extension { // phpcs:ignore PSR1.Classe
     Events::SUITE_AFTER => 'checkErrorsAfterTests',
   ];
 
-  function checkErrorsAfterTests(SuiteEvent $e) {
+  public function checkErrorsAfterTests(SuiteEvent $e) {
     $branch = getenv('CIRCLE_BRANCH');
     $skipped = $e->getResult()->skipped();
     if (in_array($branch, ['master', 'release']) && (count($skipped) !== 0)) {
diff --git a/tests/_support/CleanupExtension.php b/tests/_support/CleanupExtension.php
index 25b9f0408d..34f9d8c3df 100644
--- a/tests/_support/CleanupExtension.php
+++ b/tests/_support/CleanupExtension.php
@@ -24,13 +24,13 @@ class CleanupExtension extends Extension { // phpcs:ignore PSR1.Classes.ClassDec
   /** @var PDO */
   private $root_connection;
 
-  function __construct($config, $options) {
+  public function __construct($config, $options) {
     parent::__construct($config, $options);
     $this->root_connection = new PDO($this->createDsnConnectionString(), self::DB_USERNAME, self::DB_PASSWORD);
     $this->root_connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
   }
 
-  function backupDatabase(SuiteEvent $event) {
+  public function backupDatabase(SuiteEvent $event) {
     exec($this->createMysqlDumpCommand());
     $sql = file_get_contents(self::DB_BACKUP_PATH);
 
@@ -65,7 +65,7 @@ class CleanupExtension extends Extension { // phpcs:ignore PSR1.Classes.ClassDec
     file_put_contents(self::DB_BACKUP_PATH, $sql);
   }
 
-  function cleanupEnvironment(TestEvent $event) {
+  public function cleanupEnvironment(TestEvent $event) {
     $this->root_connection->exec(file_get_contents(self::DB_BACKUP_PATH));
     exec('rm -rf ' . self::MAILHOG_DATA_PATH . '/*', $output);
 
diff --git a/tests/_support/ErrorsExtension.php b/tests/_support/ErrorsExtension.php
index c04351ed40..4dfc469241 100644
--- a/tests/_support/ErrorsExtension.php
+++ b/tests/_support/ErrorsExtension.php
@@ -21,13 +21,13 @@ class ErrorsExtension extends Extension { // phpcs:ignore PSR1.Classes.ClassDecl
     Events::SUITE_AFTER => 'processErrorsAfterSuite',
   ];
 
-  function loadErrorCountsBeforeSuite() {
+  public function loadErrorCountsBeforeSuite() {
     foreach (self::ERROR_LOG_PATHS as $path) {
       $this->known_error_counts[$path] = count($this->readFileToArray($path));
     }
   }
 
-  function checkErrorsAfterTest(TestEvent $e) {
+  public function checkErrorsAfterTest(TestEvent $e) {
     foreach (self::ERROR_LOG_PATHS as $path) {
       $errors = $this->readFileToArray($path);
       foreach (array_slice($errors, $this->known_error_counts[$path]) as $error) {
@@ -38,7 +38,7 @@ class ErrorsExtension extends Extension { // phpcs:ignore PSR1.Classes.ClassDecl
     }
   }
 
-  function processErrorsAfterSuite(SuiteEvent $event) {
+  public function processErrorsAfterSuite(SuiteEvent $event) {
     foreach ($this->errors as $error) {
       list($test, $exception) = $error;
       $event->getResult()->addFailure($test, $exception, microtime(true));
diff --git a/tests/_support/Helper/Acceptance.php b/tests/_support/Helper/Acceptance.php
index 8a9b1c8611..3cedafa868 100644
--- a/tests/_support/Helper/Acceptance.php
+++ b/tests/_support/Helper/Acceptance.php
@@ -17,7 +17,7 @@ class Acceptance extends \Codeception\Module
    * Note: Selenium JS error log buffer is cleared after logs retrieval:
    * https://github.com/SeleniumHQ/selenium/wiki/Logging#retrieval-of-logs
    */
-  function seeNoJSErrors() {
+  public function seeNoJSErrors() {
     $wd = $this->getModule('WPWebDriver');
     assert($wd instanceof WebDriver);
 
@@ -46,7 +46,7 @@ class Acceptance extends \Codeception\Module
     $this->assertEquals('', join(PHP_EOL, $this->js_errors), 'JS errors are present');
   }
 
-  function getCurrentUrl() {
+  public function getCurrentUrl() {
     $wd = $this->getModule('WPWebDriver');
     assert($wd instanceof WebDriver);
     return $wd->_getCurrentUri();
@@ -62,7 +62,7 @@ class Acceptance extends \Codeception\Module
       );
   }
 
-  function _after(TestInterface $test) {
+  public function _after(TestInterface $test) {
     $this->js_errors = [];
   }
 }
diff --git a/tests/_support/Helper/WordPress.php b/tests/_support/Helper/WordPress.php
index 2cc3da7dc4..d282bbadf6 100644
--- a/tests/_support/Helper/WordPress.php
+++ b/tests/_support/Helper/WordPress.php
@@ -9,19 +9,19 @@ class WordPress extends \Codeception\Module
 {
   private static $functions_to_intercept = [];
 
-  static function interceptFunction($function_name, $callback) {
+  public static function interceptFunction($function_name, $callback) {
     self::$functions_to_intercept[$function_name] = $callback;
   }
 
-  static function releaseFunction($function_name) {
+  public static function releaseFunction($function_name) {
     unset(self::$functions_to_intercept[$function_name]);
   }
 
-  static function releaseAllFunctions() {
+  public static function releaseAllFunctions() {
     self::$functions_to_intercept = [];
   }
 
-  static function getInterceptor($function_name) {
+  public static function getInterceptor($function_name) {
     if (isset(self::$functions_to_intercept[$function_name]))
       return self::$functions_to_intercept[$function_name];
   }
diff --git a/tests/_support/Helper/WordPressHooks.php b/tests/_support/Helper/WordPressHooks.php
index 5130db7171..567a9471cb 100644
--- a/tests/_support/Helper/WordPressHooks.php
+++ b/tests/_support/Helper/WordPressHooks.php
@@ -12,80 +12,80 @@ class WordPressHooks extends \Codeception\Module
   private static $actions_done = [];
   private static $actions_added = [];
 
-  static function interceptApplyFilters() {
+  public static function interceptApplyFilters() {
     WordPress::interceptFunction('apply_filters', [__CLASS__, 'applyFilters']);
   }
 
-  static function interceptAddFilter() {
+  public static function interceptAddFilter() {
     WordPress::interceptFunction('add_filter', [__CLASS__, 'addFilter']);
   }
 
-  static function interceptDoAction() {
+  public static function interceptDoAction() {
     WordPress::interceptFunction('do_action', [__CLASS__, 'doAction']);
   }
 
-  static function interceptAddAction() {
+  public static function interceptAddAction() {
     WordPress::interceptFunction('add_action', [__CLASS__, 'addAction']);
   }
 
-  static function applyFilters() {
+  public static function applyFilters() {
     $args = func_get_args();
     $hook_name = array_shift($args);
     self::$filters_applied[$hook_name] = $args;
     return func_get_arg(1);
   }
 
-  static function addFilter() {
+  public static function addFilter() {
     $args = func_get_args();
     $hook_name = array_shift($args);
     self::$filters_added[$hook_name] = $args;
   }
 
-  static function doAction() {
+  public static function doAction() {
     $args = func_get_args();
     $hook_name = array_shift($args);
     self::$actions_done[$hook_name] = $args;
   }
 
-  static function addAction() {
+  public static function addAction() {
     $args = func_get_args();
     $hook_name = array_shift($args);
     self::$actions_added[$hook_name] = $args;
   }
 
-  static function isFilterApplied($hook_name) {
+  public static function isFilterApplied($hook_name) {
     return isset(self::$filters_applied[$hook_name]);
   }
 
-  static function isFilterAdded($hook_name) {
+  public static function isFilterAdded($hook_name) {
     return isset(self::$filters_added[$hook_name]);
   }
 
-  static function isActionDone($hook_name) {
+  public static function isActionDone($hook_name) {
     return isset(self::$actions_done[$hook_name]);
   }
 
-  static function isActionAdded($hook_name) {
+  public static function isActionAdded($hook_name) {
     return isset(self::$actions_added[$hook_name]);
   }
 
-  static function getFilterApplied($hook_name) {
+  public static function getFilterApplied($hook_name) {
     return self::isFilterApplied($hook_name) ? self::$filters_applied[$hook_name] : null;
   }
 
-  static function getFilterAdded($hook_name) {
+  public static function getFilterAdded($hook_name) {
     return self::isFilterAdded($hook_name) ? self::$filters_added[$hook_name] : null;
   }
 
-  static function getActionDone($hook_name) {
+  public static function getActionDone($hook_name) {
     return self::isActionDone($hook_name) ? self::$actions_done[$hook_name] : null;
   }
 
-  static function getActionAdded($hook_name) {
+  public static function getActionAdded($hook_name) {
     return self::isActionAdded($hook_name) ? self::$actions_added[$hook_name] : null;
   }
 
-  static function releaseAllHooks() {
+  public static function releaseAllHooks() {
     WordPress::releaseAllFunctions();
     self::$filters_applied = [];
     self::$filters_added = [];
diff --git a/tests/_support/IntegrationTester.php b/tests/_support/IntegrationTester.php
index 19bb96294e..31ab2dcac5 100644
--- a/tests/_support/IntegrationTester.php
+++ b/tests/_support/IntegrationTester.php
@@ -20,13 +20,13 @@ class IntegrationTester extends \Codeception\Actor { // phpcs:ignore PSR1.Classe
   use _generated\IntegrationTesterActions;
 
   // generate random users
-  function generateSubscribers($count, $data = []) {
+  public function generateSubscribers($count, $data = []) {
     for ($i = 0; $i < $count; $i++) {
       $this->generateSubscriber($data);
     }
   }
 
-  function generateSubscriber($data = []) {
+  public function generateSubscriber($data = []) {
     $subscriber_data = [
       'email' => sprintf('user%s@mailpoet.com', bin2hex(random_bytes(7))), // phpcs:ignore PHPCompatibility
       'first_name' => $this->generateName(),
diff --git a/tests/_support/UnitTester.php b/tests/_support/UnitTester.php
index ad59e4d1b4..3d29ad8b16 100644
--- a/tests/_support/UnitTester.php
+++ b/tests/_support/UnitTester.php
@@ -20,13 +20,13 @@ class UnitTester extends \Codeception\Actor { // phpcs:ignore PSR1.Classes.Class
   use _generated\UnitTesterActions;
 
   // generate random users
-  function generateSubscribers($count, $data = []) {
+  public function generateSubscribers($count, $data = []) {
     for ($i = 0; $i < $count; $i++) {
       $this->generateSubscriber($data);
     }
   }
 
-  function generateSubscriber($data = []) {
+  public function generateSubscriber($data = []) {
     $subscriber_data = [
       'email' => sprintf('user%s@mailpoet.com', bin2hex(random_bytes(7))), // phpcs:ignore PHPCompatibility
       'first_name' => $this->generateName(),
diff --git a/tests/acceptance/AddSendingKeyCest.php b/tests/acceptance/AddSendingKeyCest.php
index f4774e9afc..6a884541d1 100644
--- a/tests/acceptance/AddSendingKeyCest.php
+++ b/tests/acceptance/AddSendingKeyCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use Codeception\Scenario;
 
 class AddSendingKeyCest {
-  function addMailPoetSendingKey(\AcceptanceTester $I, Scenario $scenario) {
+  public function addMailPoetSendingKey(\AcceptanceTester $I, Scenario $scenario) {
     $I->wantTo('Add a mailpoet sending key');
 
     $mailPoetSendingKey = getenv('WP_TEST_MAILER_MAILPOET_API');
diff --git a/tests/acceptance/AdvancedSettingsCest.php b/tests/acceptance/AdvancedSettingsCest.php
index ddbcbdd0fc..ebd430e301 100644
--- a/tests/acceptance/AdvancedSettingsCest.php
+++ b/tests/acceptance/AdvancedSettingsCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class AdvancedSettingsCest {
-  function toggleAnonymousDataSetting(\AcceptanceTester $I) {
+  public function toggleAnonymousDataSetting(\AcceptanceTester $I) {
     $I->wantTo('Confirm anonymous data settings can be toggled on Advanced Settings Page');
     $noAnonymousData = '[data-automation-id="analytics-no"]';
     $yesAnonymousData = '[data-automation-id="analytics-yes"]';
@@ -25,7 +25,7 @@ class AdvancedSettingsCest {
     $I->seeOptionIsSelected($yesAnonymousData, 'Yes');
   }
 
-  function addBounceEmailAddress(\AcceptanceTester $I) {
+  public function addBounceEmailAddress(\AcceptanceTester $I) {
     $I->wantTo('Add a bounce email address on Advanced Settings page');
     $bounceAddressField = '[data-automation-id="bounce-address-field"]';
     $bounceAddressText = 'bounce@bounce.bounce';
@@ -47,7 +47,7 @@ class AdvancedSettingsCest {
     $I->waitForText($bounceAddressText);
   }
 
-  function toggleTaskScheduler(\AcceptanceTester $I) {
+  public function toggleTaskScheduler(\AcceptanceTester $I) {
     $I->wantTo('Toggle the newsletter task schedule between cron options');
     $chooseWordPressCron = '[data-automation-id="wordress_cron_radio"]';
     $chooseMailPoetCron = '[data-automation-id="mailpoet_cron_radio"]';
@@ -103,7 +103,7 @@ class AdvancedSettingsCest {
     $I->waitForText($systemInfoWordPressCron);
   }
 
-  function toggleLogging(\AcceptanceTester $I) {
+  public function toggleLogging(\AcceptanceTester $I) {
     $I->wantTo('Toggle logging options and confirm output');
     $loggingSelectBox = '[data-automation-id="logging-select-box"]';
     $chooseLogEverything = '[data-automation-id="log-everything"]';
@@ -140,7 +140,7 @@ class AdvancedSettingsCest {
     $I->waitForElement($chooseLogErrors);
   }
 
-  function checkInactiveSubscribers(\AcceptanceTester $I) {
+  public function checkInactiveSubscribers(\AcceptanceTester $I) {
     $I->wantTo('Check that inactive subsribers has default value');
     $inactiveSubscribersDefault = '[data-automation-id="inactive-subscribers-default"]';
     $I->login();
diff --git a/tests/acceptance/AuthorizedEmailAddressesValidationCest.php b/tests/acceptance/AuthorizedEmailAddressesValidationCest.php
index aa61c2f7cb..ebcdc92eb9 100644
--- a/tests/acceptance/AuthorizedEmailAddressesValidationCest.php
+++ b/tests/acceptance/AuthorizedEmailAddressesValidationCest.php
@@ -8,13 +8,13 @@ use MailPoet\Test\DataFactories\Settings;
 use MailPoetVendor\Carbon\Carbon;
 
 class AuthorizedEmailAddressesValidationCest {
-  function _before(\AcceptanceTester $I, Scenario $scenario) {
+  public function _before(\AcceptanceTester $I, Scenario $scenario) {
     if (!getenv('WP_TEST_MAILER_MAILPOET_API')) {
       $scenario->skip("Skipping, 'WP_TEST_MAILER_MAILPOET_API' not set.");
     }
   }
 
-  function authorizedEmailsValidation(\AcceptanceTester $I) {
+  public function authorizedEmailsValidation(\AcceptanceTester $I) {
     $unauthorized_sending_email = 'unauthorized1@email.com';
     $error_message_prefix = 'Sending all of your emails has been paused because your email address ';
     $error_notice_element = '[data-notice="unauthorized-email-addresses-notice"]';
@@ -42,7 +42,7 @@ class AuthorizedEmailAddressesValidationCest {
     $I->cantSee($error_message_prefix);
   }
 
-  function authorizedEmailsInNewslettersValidation(\AcceptanceTester $I) {
+  public function authorizedEmailsInNewslettersValidation(\AcceptanceTester $I) {
     $subject = 'Subject Unauthorized Welcome Email';
     (new Newsletter())->withSubject($subject)
       ->withActiveStatus()
@@ -77,7 +77,7 @@ class AuthorizedEmailAddressesValidationCest {
     $I->cantSee('Update the from address of Subject 1');
   }
 
-  function validationBeforeSendingNewsletter(\AcceptanceTester $I) {
+  public function validationBeforeSendingNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Validate from address before sending newsletter');
 
     $settings = new Settings();
diff --git a/tests/acceptance/ConfirmConfirmationPageCest.php b/tests/acceptance/ConfirmConfirmationPageCest.php
index dfd3c6b10d..c7d8eb08b4 100644
--- a/tests/acceptance/ConfirmConfirmationPageCest.php
+++ b/tests/acceptance/ConfirmConfirmationPageCest.php
@@ -3,7 +3,7 @@
  namespace MailPoet\Test\Acceptance;
 
 class ConfirmConfirmationPageCest {
-  function confirmDefaultConfirmationPage(\AcceptanceTester $I) {
+  public function confirmDefaultConfirmationPage(\AcceptanceTester $I) {
     $I->wantTo('Confirm link to default confirmation page works correctly');
     $I->login();
     $I->amOnMailPoetPage('Settings');
diff --git a/tests/acceptance/ConfirmNewsletterAutosaveCest.php b/tests/acceptance/ConfirmNewsletterAutosaveCest.php
index 5cc24a7d13..0996277b7b 100644
--- a/tests/acceptance/ConfirmNewsletterAutosaveCest.php
+++ b/tests/acceptance/ConfirmNewsletterAutosaveCest.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Acceptance;
 
 class ConfirmNewsletterAutosaveCest {
 
-  function confirmNewsletterAutoSave(\AcceptanceTester $I) {
+  public function confirmNewsletterAutoSave(\AcceptanceTester $I) {
     $I->wantTo('Confirm autosave works as advertised');
 
     $newsletter_title = 'Autosave Test ' . \MailPoet\Util\Security::generateRandomString();
diff --git a/tests/acceptance/ConfirmNotificationAutosaveCest.php b/tests/acceptance/ConfirmNotificationAutosaveCest.php
index c28438f6e6..c70abcb3c8 100644
--- a/tests/acceptance/ConfirmNotificationAutosaveCest.php
+++ b/tests/acceptance/ConfirmNotificationAutosaveCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class ConfirmNotificationAutosaveCest {
 
-  function confirmNotificationAutosave(\AcceptanceTester $I) {
+  public function confirmNotificationAutosave(\AcceptanceTester $I) {
     $I->wantTo('Confirm Post Notification Autosave');
     $newsletter_title = 'Notification Autosave Test';
     // step 1 - Prepare post notification data
diff --git a/tests/acceptance/ConfirmTitleAlignmentSettingsInALCBlockCest.php b/tests/acceptance/ConfirmTitleAlignmentSettingsInALCBlockCest.php
index 36bca92a10..a3e58e4405 100644
--- a/tests/acceptance/ConfirmTitleAlignmentSettingsInALCBlockCest.php
+++ b/tests/acceptance/ConfirmTitleAlignmentSettingsInALCBlockCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class ConfirmTitleAlignmentSettingsInALCBlockCest {
 
-  function createWelcomeNewsletter(\AcceptanceTester $I) {
+  public function createWelcomeNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Confirm title alignment settings in ALC block');
 
     // create a post and a newsletter with ALC block
diff --git a/tests/acceptance/CreateNewSegmentCest.php b/tests/acceptance/CreateNewSegmentCest.php
index 1ca3d1613a..239b38d504 100644
--- a/tests/acceptance/CreateNewSegmentCest.php
+++ b/tests/acceptance/CreateNewSegmentCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class CreateNewSegmentCest {
-  function createUserRoleSegment(\AcceptanceTester $I) {
+  public function createUserRoleSegment(\AcceptanceTester $I) {
     $I->wantTo('Create a new WP user role segment');
     $segment_title = 'Create User Role Segment Test';
     $I->login();
@@ -21,7 +21,7 @@ class CreateNewSegmentCest {
     $I->waitForText($segment_title, 20);
   }
 
-  function createEmailSegment(\AcceptanceTester $I) {
+  public function createEmailSegment(\AcceptanceTester $I) {
     $I->wantTo('Create a new email segment');
     $email_subject = 'Segment Email Test';
     $newsletter_factory = new Newsletter();
diff --git a/tests/acceptance/CreateWelcomeEmailCest.php b/tests/acceptance/CreateWelcomeEmailCest.php
index 7d0deeded8..9eda612a3a 100644
--- a/tests/acceptance/CreateWelcomeEmailCest.php
+++ b/tests/acceptance/CreateWelcomeEmailCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class CreateWelcomeEmailCest {
-  function createWelcomeNewsletter(\AcceptanceTester $I) {
+  public function createWelcomeNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Create and configure welcome newsletter');
     $newsletter_title = 'Create Welcome Email';
     $I->login();
diff --git a/tests/acceptance/CreateWooCommerceNewsletterCest.php b/tests/acceptance/CreateWooCommerceNewsletterCest.php
index 6d4e608d58..ab1c32abf5 100644
--- a/tests/acceptance/CreateWooCommerceNewsletterCest.php
+++ b/tests/acceptance/CreateWooCommerceNewsletterCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Features;
 
 class CreateWooCommerceNewsletterCest {
 
-  function createFirstPurchaseEmail(\AcceptanceTester $I) {
+  public function createFirstPurchaseEmail(\AcceptanceTester $I) {
     $I->wantTo('Create and configure a first purchase automatic email');
 
     $newsletter_title = 'First Purchase Email Creation';
@@ -40,7 +40,7 @@ class CreateWooCommerceNewsletterCest {
     $I->see('Email sent when a customer makes their first purchase.', $newsletter_listing_element);
   }
 
-  function createAbandonedCartEmail(\AcceptanceTester $I) {
+  public function createAbandonedCartEmail(\AcceptanceTester $I) {
     $I->wantTo('Create and configure an abandoned cart automatic email');
 
     $newsletter_title = 'Abandoned Cart Email Creation';
diff --git a/tests/acceptance/CustomUnsubscribePageCest.php b/tests/acceptance/CustomUnsubscribePageCest.php
index 274df91c21..429c78658e 100644
--- a/tests/acceptance/CustomUnsubscribePageCest.php
+++ b/tests/acceptance/CustomUnsubscribePageCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class CustomUnsubscribePageCest {
-  function createCustomUnsubscribePage(\AcceptanceTester $I) {
+  public function createCustomUnsubscribePage(\AcceptanceTester $I) {
     $I->wantTo('Create page with MP subscriber shortcode');
     $pageTitle = 'SorryToSeeYouGo';
     $pageText = 'Manage your subscription';
diff --git a/tests/acceptance/DeleteAutomaticWooCommerceEmailCest.php b/tests/acceptance/DeleteAutomaticWooCommerceEmailCest.php
index 944f37536a..e873aa880a 100644
--- a/tests/acceptance/DeleteAutomaticWooCommerceEmailCest.php
+++ b/tests/acceptance/DeleteAutomaticWooCommerceEmailCest.php
@@ -6,11 +6,11 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DeleteAutomaticWooCommerceEmailCest {
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
   }
 
-  function trashAutomaticWooCommerceEmail(\AcceptanceTester $I) {
+  public function trashAutomaticWooCommerceEmail(\AcceptanceTester $I) {
     $newsletter_name = 'Trash Automatic WooCommerce Email Test';
 
     $newsletter_factory = new Newsletter();
@@ -30,7 +30,7 @@ class DeleteAutomaticWooCommerceEmailCest {
     $I->waitForText($newsletter_name);
   }
 
-  function restoreTrashedAutomaticWooCommerceEmail(\AcceptanceTester $I) {
+  public function restoreTrashedAutomaticWooCommerceEmail(\AcceptanceTester $I) {
     $newsletter_name = 'Restore Trashed Automatic WooCommerce Email Test';
 
     $newsletter_factory = new Newsletter();
@@ -53,7 +53,7 @@ class DeleteAutomaticWooCommerceEmailCest {
     $I->waitForText($newsletter_name);
   }
 
-  function deleteTrashedAutomaticWooCommerceEmail(\AcceptanceTester $I) {
+  public function deleteTrashedAutomaticWooCommerceEmail(\AcceptanceTester $I) {
     $newsletter_name = 'Delete Trashed Automatic WooCommerce Email Test';
 
     $newsletter_factory = new Newsletter();
diff --git a/tests/acceptance/DeleteNewsletterCest.php b/tests/acceptance/DeleteNewsletterCest.php
index c2a92bbbaf..3bd0a3d186 100644
--- a/tests/acceptance/DeleteNewsletterCest.php
+++ b/tests/acceptance/DeleteNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DeleteNewsletterCest {
 
-  function moveNewsletterToTrash(\AcceptanceTester $I) {
+  public function moveNewsletterToTrash(\AcceptanceTester $I) {
     $newsletter_name = 'Trash Newsletter';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletter_name)->create();
@@ -21,7 +21,7 @@ class DeleteNewsletterCest {
     $I->waitForText($newsletter_name);
   }
 
-  function restoreFormFromTrash(\AcceptanceTester $I) {
+  public function restoreFormFromTrash(\AcceptanceTester $I) {
     $newsletter_name = 'Restore Trashed Newsletter';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletter_name)->withDeleted()->create();
@@ -38,7 +38,7 @@ class DeleteNewsletterCest {
     $I->waitForText($newsletter_name);
   }
 
-  function deleteFormPermanently(\AcceptanceTester $I) {
+  public function deleteFormPermanently(\AcceptanceTester $I) {
     $newsletter_name = 'Goodbye Forever Newsletter';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletter_name)->withDeleted()->create();
diff --git a/tests/acceptance/DeleteNotificationCest.php b/tests/acceptance/DeleteNotificationCest.php
index 4b984736db..0e01994f9b 100644
--- a/tests/acceptance/DeleteNotificationCest.php
+++ b/tests/acceptance/DeleteNotificationCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DeleteNotificationCest {
 
-  function deleteNotification(\AcceptanceTester $I) {
+  public function deleteNotification(\AcceptanceTester $I) {
     // step 1 - Prepare post notification data
     $I->wantTo('delete a notification');
     $newsletter_name = 'Deletion Test Post Notification';
@@ -26,7 +26,7 @@ class DeleteNotificationCest {
     $I->waitForText($newsletter_name);
   }
 
-  function restoreNotificationFromTrash(\AcceptanceTester $I) {
+  public function restoreNotificationFromTrash(\AcceptanceTester $I) {
     // step 1 - Prepare post notification data
     $I->wantTo('Restore a newsletter from trash');
     $newsletter_name = 'Restore from Trash Test Post Notification';
@@ -49,7 +49,7 @@ class DeleteNotificationCest {
     $I->waitForText($newsletter_name);
   }
 
-  function deleteNotificationPermanently(\AcceptanceTester $I) {
+  public function deleteNotificationPermanently(\AcceptanceTester $I) {
     // step 1 - Prepare post notification data
     $I->wantTo('Permanently delete a notification');
     $newsletter_name = 'Goodbye Forever Notification Test';
diff --git a/tests/acceptance/DeleteNotificationHistoryCest.php b/tests/acceptance/DeleteNotificationHistoryCest.php
index 8047fae656..32c22075ec 100644
--- a/tests/acceptance/DeleteNotificationHistoryCest.php
+++ b/tests/acceptance/DeleteNotificationHistoryCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DeleteNotificationHistoryCest {
 
-  function delete(\AcceptanceTester $I) {
+  public function delete(\AcceptanceTester $I) {
     // step 1 - Prepare data
     $I->wantTo('delete a notification history');
     $newsletter_name = 'Post notification history';
diff --git a/tests/acceptance/DeleteTrashedSegmentCest.php b/tests/acceptance/DeleteTrashedSegmentCest.php
index 6bfafaec14..4cfa244375 100644
--- a/tests/acceptance/DeleteTrashedSegmentCest.php
+++ b/tests/acceptance/DeleteTrashedSegmentCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\DynamicSegment;
 
 class DeleteTrashedSegmentCest {
-  function deleteSegmentFromTrash(\AcceptanceTester $I) {
+  public function deleteSegmentFromTrash(\AcceptanceTester $I) {
     $I->wantTo('Delete a segment from trash');
 
     $segment_title = 'Delete Segment From Trash Test';
diff --git a/tests/acceptance/DuplicateAutomaticEmailCest.php b/tests/acceptance/DuplicateAutomaticEmailCest.php
index 4cb9842944..e398c3a0d6 100644
--- a/tests/acceptance/DuplicateAutomaticEmailCest.php
+++ b/tests/acceptance/DuplicateAutomaticEmailCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class DuplicateAutomaticEmailCest {
-  function duplicateAutomaticEmail(\AcceptanceTester $I) {
+  public function duplicateAutomaticEmail(\AcceptanceTester $I) {
     $I->wantTo('Duplicate an automatic email');
     $I->activateWooCommerce();
     $email_subject = 'Duplicate Automatic Email Test';
diff --git a/tests/acceptance/DuplicateNewsletterCest.php b/tests/acceptance/DuplicateNewsletterCest.php
index 54f084d25e..f02c332739 100644
--- a/tests/acceptance/DuplicateNewsletterCest.php
+++ b/tests/acceptance/DuplicateNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DuplicateNewsletterCest {
 
-  function duplicateNewsletter(\AcceptanceTester $I) {
+  public function duplicateNewsletter(\AcceptanceTester $I) {
     $newsletter_name = 'Duplicate Newsletter';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletter_name)->create();
diff --git a/tests/acceptance/DuplicatePostNotificationCest.php b/tests/acceptance/DuplicatePostNotificationCest.php
index dfd3573fce..5ad9b6f7a4 100644
--- a/tests/acceptance/DuplicatePostNotificationCest.php
+++ b/tests/acceptance/DuplicatePostNotificationCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class DuplicatePostNotificationCest {
 
-  function duplicatePostNotification(\AcceptanceTester $I) {
+  public function duplicatePostNotification(\AcceptanceTester $I) {
     $I->wantTo('Duplicate post notification email');
 
     // step 1 - Prepare post notification email
diff --git a/tests/acceptance/EditAutomaticWooCommerceEmailCest.php b/tests/acceptance/EditAutomaticWooCommerceEmailCest.php
index 6ecbe2995f..08250d5218 100644
--- a/tests/acceptance/EditAutomaticWooCommerceEmailCest.php
+++ b/tests/acceptance/EditAutomaticWooCommerceEmailCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditAutomaticWooCommerceEmailCest {
-  function dontSeeWooCommerceTabWhenWooCommerceIsNotActive(\AcceptanceTester $I) {
+  public function dontSeeWooCommerceTabWhenWooCommerceIsNotActive(\AcceptanceTester $I) {
     $I->wantTo('Not see WooCommerce tab');
     $I->deactivateWooCommerce();
     $I->login();
@@ -13,7 +13,7 @@ class EditAutomaticWooCommerceEmailCest {
     $I->dontSee('[data-automation-id="tab-WooCommerce"]');
   }
 
-  function editAutomaticWooCommerceEmail(\AcceptanceTester $I) {
+  public function editAutomaticWooCommerceEmail(\AcceptanceTester $I) {
     $newsletter_name = 'Edit Automatic WooCommerce Email Test';
     $newsletter_edited_name = 'Edit Automatic WooCommerce Email Test Edited';
 
diff --git a/tests/acceptance/EditExistingNewsletterCest.php b/tests/acceptance/EditExistingNewsletterCest.php
index 9bf3bb05a0..80d0bde89e 100644
--- a/tests/acceptance/EditExistingNewsletterCest.php
+++ b/tests/acceptance/EditExistingNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class EditExistingNewsletterCest {
 
-  function editExistingNewsletter(\AcceptanceTester $I) {
+  public function editExistingNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Edit a standard newsletter');
     $newsletterTitle = 'Unedited Standard Title';
     $editedNewsletterTitle = "Edited Standard Title";
diff --git a/tests/acceptance/EditExistingPostNotificationEmailCest.php b/tests/acceptance/EditExistingPostNotificationEmailCest.php
index 8a5598f044..e63169556b 100644
--- a/tests/acceptance/EditExistingPostNotificationEmailCest.php
+++ b/tests/acceptance/EditExistingPostNotificationEmailCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class EditExistingPostNotificationEmailCest {
 
-  function editSubjectAndSchedule(\AcceptanceTester $I) {
+  public function editSubjectAndSchedule(\AcceptanceTester $I) {
     $I->wantTo('Edit existing post notification email');
 
     $newsletter_title = 'Edit Test Post Notification';
diff --git a/tests/acceptance/EditExistingSegmentCest.php b/tests/acceptance/EditExistingSegmentCest.php
index ea1a48ed96..d6afd827f7 100644
--- a/tests/acceptance/EditExistingSegmentCest.php
+++ b/tests/acceptance/EditExistingSegmentCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\DynamicSegment;
 
 class EditExistingSegmentCest {
-  function editUserRoleSegment(\AcceptanceTester $I) {
+  public function editUserRoleSegment(\AcceptanceTester $I) {
     $I->wantTo('Edit an existing WP user role segment');
 
     $segment_title = 'Edit User Role Segment Test';
diff --git a/tests/acceptance/EditSignUpConfirmationEmailCest.php b/tests/acceptance/EditSignUpConfirmationEmailCest.php
index 09862233b3..19dc3e60d7 100644
--- a/tests/acceptance/EditSignUpConfirmationEmailCest.php
+++ b/tests/acceptance/EditSignUpConfirmationEmailCest.php
@@ -8,7 +8,7 @@ use MailPoet\Test\DataFactories\Settings;
 
 class EditSignUpConfirmationEmailCest {
 
-  function edit(\AcceptanceTester $I) {
+  public function edit(\AcceptanceTester $I) {
     $I->wantTo('Edit sign up confirmation email');
 
     // make sure sign up confirmation is enabled
diff --git a/tests/acceptance/EditorDividerBlockCest.php b/tests/acceptance/EditorDividerBlockCest.php
index 549b8fbdcf..57c0a75c5f 100644
--- a/tests/acceptance/EditorDividerBlockCest.php
+++ b/tests/acceptance/EditorDividerBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorDividerBlockCest {
-  function addDivider(\AcceptanceTester $I) {
+  public function addDivider(\AcceptanceTester $I) {
     $I->wantTo('add divider block to newsletter');
     $dividerSettings = ('[data-automation-id="settings_tool"]');
     $dividerResizeHandle = ('[data-automation-id="divider_resize_handle"]');
diff --git a/tests/acceptance/EditorFooterBlockCest.php b/tests/acceptance/EditorFooterBlockCest.php
index 555da14bcd..f9aff3c490 100644
--- a/tests/acceptance/EditorFooterBlockCest.php
+++ b/tests/acceptance/EditorFooterBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorFooterBlockCest {
-  function addFooter(\AcceptanceTester $I) {
+  public function addFooter(\AcceptanceTester $I) {
     $I->wantTo('add Footer block to newsletter');
     $footerInEditor = ('[data-automation-id="footer"]');
     $footerSettingsIcon = ('[data-automation-id="settings_tool"]');
diff --git a/tests/acceptance/EditorHeaderBlockCest.php b/tests/acceptance/EditorHeaderBlockCest.php
index ef3e1210ac..7e88bd1e15 100644
--- a/tests/acceptance/EditorHeaderBlockCest.php
+++ b/tests/acceptance/EditorHeaderBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorHeaderBlockCest {
-  function addHeader(\AcceptanceTester $I) {
+  public function addHeader(\AcceptanceTester $I) {
     $I->wantTo('add header block to newsletter');
     $headerInEditor = ('[data-automation-id="header"]');
     $headerSettingsIcon = ('[data-automation-id="settings_tool"]');
diff --git a/tests/acceptance/EditorHistoryCest.php b/tests/acceptance/EditorHistoryCest.php
index 0f044fdc0e..a9062ff1fb 100644
--- a/tests/acceptance/EditorHistoryCest.php
+++ b/tests/acceptance/EditorHistoryCest.php
@@ -11,7 +11,7 @@ class EditorHistoryCest {
   const UNDO_SELECTOR = '#mailpoet-history-arrow-undo';
   const INACTIVE_SELECTOR = '.mailpoet_history_arrow_inactive';
 
-  function undoRedo(\AcceptanceTester $I) {
+  public function undoRedo(\AcceptanceTester $I) {
     $I->wantTo('Undo and redo');
     $newsletter = (new Newsletter())
         ->loadBodyFrom('newsletterWithText.json')
diff --git a/tests/acceptance/EditorImageBlockCest.php b/tests/acceptance/EditorImageBlockCest.php
index 7b49c08df0..b700b48cb5 100644
--- a/tests/acceptance/EditorImageBlockCest.php
+++ b/tests/acceptance/EditorImageBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorImageBlockCest {
-  function addImage(\AcceptanceTester $I) {
+  public function addImage(\AcceptanceTester $I) {
     $I->wantTo('add image block to newsletter');
     $I->cli(['media', 'import', '/wp-core/wp-content/plugins/mailpoet/tests/_data/unicornsplaceholder.png']);
     $newsletter = (new Newsletter())
diff --git a/tests/acceptance/EditorLineHeightCest.php b/tests/acceptance/EditorLineHeightCest.php
index cae704b26e..f1f4c13058 100644
--- a/tests/acceptance/EditorLineHeightCest.php
+++ b/tests/acceptance/EditorLineHeightCest.php
@@ -7,7 +7,7 @@ use Facebook\WebDriver\WebDriverBy;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorLineHeightCest {
-  function changeLineHeight(\AcceptanceTester $I) {
+  public function changeLineHeight(\AcceptanceTester $I) {
     $textSize = '10';
     $h1Size = '40';
     $h2Size = '30';
diff --git a/tests/acceptance/EditorProductsCest.php b/tests/acceptance/EditorProductsCest.php
index 674f0550f7..78ce341990 100644
--- a/tests/acceptance/EditorProductsCest.php
+++ b/tests/acceptance/EditorProductsCest.php
@@ -239,7 +239,7 @@ class EditorProductsCest {
     $I->waitForElementNotVisible('.velocity-animating');
   }
 
-  function testProductsWidget(\AcceptanceTester $I) {
+  public function testProductsWidget(\AcceptanceTester $I) {
     $this->initializeNewsletter($I);
     $this->productsWidgetNotVisible($I);
     $this->initializeWooCommerce($I);
diff --git a/tests/acceptance/EditorSettingsBehaviourCest.php b/tests/acceptance/EditorSettingsBehaviourCest.php
index 1bfa0ac0ca..6355ddce9f 100644
--- a/tests/acceptance/EditorSettingsBehaviourCest.php
+++ b/tests/acceptance/EditorSettingsBehaviourCest.php
@@ -15,7 +15,7 @@ class EditorSettingsBehaviourCest {
   const HIGHLIGHTED_ALC_SELECTOR = '.mailpoet_highlight .mailpoet_automated_latest_content_block_posts';
   const SETTINGS_PANEL_SELECTOR = '#mailpoet_panel';
 
-  function testSettingsBehaviour(\AcceptanceTester $I) {
+  public function testSettingsBehaviour(\AcceptanceTester $I) {
     $I->wantTo('Test settings behaviour');
     $newsletterTitle = 'Settings Newsletter';
     $newsletter = (new Newsletter())
diff --git a/tests/acceptance/EditorSocialBlockCest.php b/tests/acceptance/EditorSocialBlockCest.php
index b78195f140..a0eb3d5457 100644
--- a/tests/acceptance/EditorSocialBlockCest.php
+++ b/tests/acceptance/EditorSocialBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorSocialBlockCest {
-  function addSocialBlock(\AcceptanceTester $I) {
+  public function addSocialBlock(\AcceptanceTester $I) {
     $I->wantTo('add social block to newsletter');
     $socialBlockInEditor = ('[data-automation-id="socialBlock"]');
     $socialBlockSettingsAssertion = ('[data-automation-id="social_select_another_network"]');
diff --git a/tests/acceptance/EditorSpacerBlockCest.php b/tests/acceptance/EditorSpacerBlockCest.php
index 03271679a0..7725a574c7 100644
--- a/tests/acceptance/EditorSpacerBlockCest.php
+++ b/tests/acceptance/EditorSpacerBlockCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class EditorSpacerBlockCest {
-  function addSpacer(\AcceptanceTester $I) {
+  public function addSpacer(\AcceptanceTester $I) {
     $I->wantTo('add spacer block to newsletter');
     $spacerResizeHandle = '[data-automation-id="spacer_resize_handle"]';
     $spacerInEditor = '[data-automation-id="spacer"]';
diff --git a/tests/acceptance/EditorTextBlockCest.php b/tests/acceptance/EditorTextBlockCest.php
index a488f7d198..646d649776 100644
--- a/tests/acceptance/EditorTextBlockCest.php
+++ b/tests/acceptance/EditorTextBlockCest.php
@@ -9,7 +9,7 @@ class EditorTextBlockCest {
   const TEXT_BLOCK_SELECTOR = '.mailpoet_text_block';
   const CONTAINER_SELECTOR = '.mailpoet_container_horizontal';
 
-  function addText(\AcceptanceTester $I) {
+  public function addText(\AcceptanceTester $I) {
     $I->wantTo('add Text block to newsletter');
     $textInEditor = ('[data-automation-id="text_block_in_editor"]');
     $newsletter = (new Newsletter())
@@ -22,7 +22,7 @@ class EditorTextBlockCest {
     $I->waitForText('Edit this to insert text.');
   }
 
-  function toolbarIsClosing(\AcceptanceTester $I) {
+  public function toolbarIsClosing(\AcceptanceTester $I) {
     $I->wantTo('Automatically close TinyMCE toolbar when clicked outside textarea');
     $textInEditor = ('[data-automation-id="text_block_in_editor"]');
     $newsletter = (new Newsletter())
diff --git a/tests/acceptance/EnableAndDisableSignupConfirmationCest.php b/tests/acceptance/EnableAndDisableSignupConfirmationCest.php
index 7154af6c75..b3405ec405 100644
--- a/tests/acceptance/EnableAndDisableSignupConfirmationCest.php
+++ b/tests/acceptance/EnableAndDisableSignupConfirmationCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Settings;
 
 class EnableAndDisableSignupConfirmationCest {
 
-  function disableSignupConfirmation(AcceptanceTester $I) {
+  public function disableSignupConfirmation(AcceptanceTester $I) {
     $settings = new Settings();
     $settings
       ->withConfirmationEmailEnabled()
@@ -20,7 +20,7 @@ class EnableAndDisableSignupConfirmationCest {
     $I->dontSee('Disable signup confirmation subject');
   }
 
-  function enableSignupConfirmation(AcceptanceTester $I) {
+  public function enableSignupConfirmation(AcceptanceTester $I) {
     $settings = new Settings();
     $settings
       ->withConfirmationEmailDisabled()
diff --git a/tests/acceptance/ExportSubscribersCest.php b/tests/acceptance/ExportSubscribersCest.php
index fd2f622281..fbf49b6372 100644
--- a/tests/acceptance/ExportSubscribersCest.php
+++ b/tests/acceptance/ExportSubscribersCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Segment;
 use MailPoet\Test\DataFactories\Subscriber;
 
 class ExportSubscribersCest {
-  function exportSubscribers(\AcceptanceTester $I) {
+  public function exportSubscribers(\AcceptanceTester $I) {
     $segment_factory = new Segment();
     $segment_name = 'Hobbyists';
     $segment = $segment_factory->withName($segment_name)->create();
diff --git a/tests/acceptance/FormEditorAddNamesCest.php b/tests/acceptance/FormEditorAddNamesCest.php
index af59ec9808..85c6339ee0 100644
--- a/tests/acceptance/FormEditorAddNamesCest.php
+++ b/tests/acceptance/FormEditorAddNamesCest.php
@@ -9,7 +9,7 @@ use MailPoet\Test\DataFactories\Segment;
 
 class FormEditorAddNamesCest {
 
-  function addNamesToAForm(\AcceptanceTester $I) {
+  public function addNamesToAForm(\AcceptanceTester $I) {
     $segment_factory = new Segment();
     $segment_name = 'Fancy List';
     $segment = $segment_factory->withName($segment_name)->create();
diff --git a/tests/acceptance/FormEditorUpdateMandatoryFieldsCest.php b/tests/acceptance/FormEditorUpdateMandatoryFieldsCest.php
index 8e47daebc9..c1fb151ec8 100644
--- a/tests/acceptance/FormEditorUpdateMandatoryFieldsCest.php
+++ b/tests/acceptance/FormEditorUpdateMandatoryFieldsCest.php
@@ -8,7 +8,7 @@ use MailPoet\Test\DataFactories\Form;
 use MailPoet\Test\DataFactories\Segment;
 
 class FormEditorUpdateMandatoryFieldsCest {
-  function updateEmailAndSubmit(\AcceptanceTester $I) {
+  public function updateEmailAndSubmit(\AcceptanceTester $I) {
     $features = new Features();
     $features->withFeatureEnabled(FeaturesController::NEW_FORM_EDITOR);
     $segment_factory = new Segment();
diff --git a/tests/acceptance/FormEditorUpdateNewFormCest.php b/tests/acceptance/FormEditorUpdateNewFormCest.php
index 6dbd27732e..927be1c283 100644
--- a/tests/acceptance/FormEditorUpdateNewFormCest.php
+++ b/tests/acceptance/FormEditorUpdateNewFormCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Features;
 use MailPoet\Test\DataFactories\Segment;
 
 class FormEditorUpdateNewFormCest {
-  function updateNewForm(\AcceptanceTester $I) {
+  public function updateNewForm(\AcceptanceTester $I) {
     $segment_factory = new Segment();
     $segment_name = 'Fancy List';
     $segment_factory->withName($segment_name)->create();
diff --git a/tests/acceptance/FormsCreationCest.php b/tests/acceptance/FormsCreationCest.php
index d6f4a6ed39..6dcf590542 100644
--- a/tests/acceptance/FormsCreationCest.php
+++ b/tests/acceptance/FormsCreationCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class FormsCreationCest {
-  function createForm(\AcceptanceTester $I) {
+  public function createForm(\AcceptanceTester $I) {
     $I->wantTo('Create a new Form');
 
     $I->login();
@@ -21,7 +21,7 @@ class FormsCreationCest {
     $I->seeNoJSErrors();
   }
 
-  function createFormWithoutAList(\AcceptanceTester $I) {
+  public function createFormWithoutAList(\AcceptanceTester $I) {
     $I->wantTo('Create a new Form');
 
     $I->login();
diff --git a/tests/acceptance/FormsDeletingCest.php b/tests/acceptance/FormsDeletingCest.php
index 7e8611f825..2434416427 100644
--- a/tests/acceptance/FormsDeletingCest.php
+++ b/tests/acceptance/FormsDeletingCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Form;
 
 class FormsDeletingCest {
 
-  function moveFormToTrash(\AcceptanceTester $I) {
+  public function moveFormToTrash(\AcceptanceTester $I) {
     $form_name = 'Move to trash form';
     $form = new Form();
     $form->withName($form_name)->create();
@@ -25,7 +25,7 @@ class FormsDeletingCest {
     $I->waitForText($form_name);
   }
 
-  function restoreFormFromTrash(\AcceptanceTester $I) {
+  public function restoreFormFromTrash(\AcceptanceTester $I) {
     $form_name = 'Restore from trash form';
     $form = new Form();
     $form->withName($form_name)->withDeleted()->create();
@@ -46,7 +46,7 @@ class FormsDeletingCest {
     $I->waitForText($form_name);
   }
 
-  function deleteFormPermanently(\AcceptanceTester $I) {
+  public function deleteFormPermanently(\AcceptanceTester $I) {
     $form_name = 'Delete form permanently';
     $form = new Form();
     $form->withName($form_name)->withDeleted()->create();
diff --git a/tests/acceptance/FormsDuplicatingCest.php b/tests/acceptance/FormsDuplicatingCest.php
index 1f47cea74a..0d6124d804 100644
--- a/tests/acceptance/FormsDuplicatingCest.php
+++ b/tests/acceptance/FormsDuplicatingCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Form;
 
 class FormsDuplicatingCest {
 
-  function duplicateForm(\AcceptanceTester $I) {
+  public function duplicateForm(\AcceptanceTester $I) {
     $form_name = 'Form for duplicate test';
     $form = new Form();
     $form->withName($form_name)->create();
diff --git a/tests/acceptance/FormsListingCest.php b/tests/acceptance/FormsListingCest.php
index a6125dba01..553a0ed6b4 100644
--- a/tests/acceptance/FormsListingCest.php
+++ b/tests/acceptance/FormsListingCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Form;
 
 class FormsListingCest {
 
-  function formsListing(\AcceptanceTester $I) {
+  public function formsListing(\AcceptanceTester $I) {
     $form = new Form();
     $form->withName('Test Form');
     $form->create();
diff --git a/tests/acceptance/ListsListingCest.php b/tests/acceptance/ListsListingCest.php
index 8ba39c7de2..f6e33604ff 100644
--- a/tests/acceptance/ListsListingCest.php
+++ b/tests/acceptance/ListsListingCest.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Acceptance;
 
 class ListsListingCest {
 
-  function listsListing(\AcceptanceTester $I) {
+  public function listsListing(\AcceptanceTester $I) {
     $I->wantTo('Open lists listings page');
 
     $I->login();
diff --git a/tests/acceptance/MailpoetMenuCest.php b/tests/acceptance/MailpoetMenuCest.php
index e874108240..b28f47d026 100644
--- a/tests/acceptance/MailpoetMenuCest.php
+++ b/tests/acceptance/MailpoetMenuCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class MailpoetMenuCest {
-  function sendEmail(\AcceptanceTester $I) {
+  public function sendEmail(\AcceptanceTester $I) {
     $I->wantTo('Use MailPoet menu in WordPress admin');
 
     $I->login();
diff --git a/tests/acceptance/ManageSubscriptionLinkCest.php b/tests/acceptance/ManageSubscriptionLinkCest.php
index 6848966d6b..ddb87d41ec 100644
--- a/tests/acceptance/ManageSubscriptionLinkCest.php
+++ b/tests/acceptance/ManageSubscriptionLinkCest.php
@@ -13,7 +13,7 @@ class ManageSubscriptionLinkCest {
   /** @var string */
   private $newsletter_title;
 
-  function __construct() {
+  public function __construct() {
     $this->newsletter_title = 'Subscription links Email ' . \MailPoet\Util\Security::generateRandomString();
   }
 
@@ -21,13 +21,13 @@ class ManageSubscriptionLinkCest {
     $this->settings = $settings;
   }
 
-  function _before() {
+  public function _before() {
     $this->settings
       ->withConfirmationEmailEnabled()
       ->withCronTriggerMethod('WordPress');
   }
 
-  function manageSubscriptionLink(\AcceptanceTester $I) {
+  public function manageSubscriptionLink(\AcceptanceTester $I) {
     $I->wantTo('Verify that "manage subscription" link works and subscriber status can be updated');
     $this->sendEmail($I);
     $I->amOnMailboxAppPage();
@@ -61,7 +61,7 @@ class ManageSubscriptionLinkCest {
     $I->seeNoJSErrors();
   }
 
-  function unsubscribeLink(\AcceptanceTester $I) {
+  public function unsubscribeLink(\AcceptanceTester $I) {
     $I->wantTo('Verify that "unsubscribe" link works and subscriber status is set to unsubscribed');
     $this->sendEmail($I);
 
diff --git a/tests/acceptance/ManageWelcomeEmailCest.php b/tests/acceptance/ManageWelcomeEmailCest.php
index 247854cbca..caa6385584 100644
--- a/tests/acceptance/ManageWelcomeEmailCest.php
+++ b/tests/acceptance/ManageWelcomeEmailCest.php
@@ -9,7 +9,7 @@ class ManageWelcomeEmailCest {
   private $welcomeTemplate;
   private $titleElement;
 
-  function __construct() {
+  public function __construct() {
     $this->welcomeTemplate = '[data-automation-id="select_template_0"]';
     $this->titleElement = '[data-automation-id="newsletter_title"]';
   }
@@ -21,7 +21,7 @@ class ManageWelcomeEmailCest {
         ->create();
   }
 
-  function saveWelcomeNewsletterAsDraft(\AcceptanceTester $I) {
+  public function saveWelcomeNewsletterAsDraft(\AcceptanceTester $I) {
     $I->wantTo('save a welcome newsletter as a draft');
     $newsletterTitle = 'Save Welcome Email As Draft Test Email';
     $I->login();
@@ -43,7 +43,7 @@ class ManageWelcomeEmailCest {
     $I->waitForText($newsletterTitle);
   }
 
-  function editWelcomeEmail(\AcceptanceTester $I) {
+  public function editWelcomeEmail(\AcceptanceTester $I) {
     $newsletter = $this->createWelcomeEmailWithTitle($I, 'Edit Welcome Email Test');
     $I->wantTo('Edit a welcome newsletter');
     $I->login();
@@ -58,7 +58,7 @@ class ManageWelcomeEmailCest {
     $I->waitForText('Edit Test Welcome Edited');
   }
 
-  function deleteWelcomeEmail(\AcceptanceTester $I) {
+  public function deleteWelcomeEmail(\AcceptanceTester $I) {
     $I->wantTo('Delete a welcome email');
     $newsletterTitle = 'Delete Welcome Email Test';
     $this->createWelcomeEmailWithTitle($I, $newsletterTitle);
@@ -76,7 +76,7 @@ class ManageWelcomeEmailCest {
     $I->waitForText($newsletterTitle);
   }
 
-  function duplicateWelcomeEmail (\AcceptanceTester $I) {
+  public function duplicateWelcomeEmail (\AcceptanceTester $I) {
     $newsletterTitle = 'Duplicate Welcome Email Test';
     $this->createWelcomeEmailWithTitle($I, $newsletterTitle);
     $I->wantTo('Duplicate a welcome email');
@@ -88,7 +88,7 @@ class ManageWelcomeEmailCest {
     $I->waitForText('Copy of ' . $newsletterTitle);
   }
 
-  function searchForWelcomeEmail (\AcceptanceTester $I) {
+  public function searchForWelcomeEmail (\AcceptanceTester $I) {
     $I->wantTo('Search for a welcome email');
     $newsletterTitle = 'Welcome Email Search Test';
     $failureConditionNewsletter = 'Totes Fake';
@@ -103,7 +103,7 @@ class ManageWelcomeEmailCest {
     $I->waitForText($newsletterTitle);
   }
 
-  function saveWelcomeEmailAsTemplate (\AcceptanceTester $I) {
+  public function saveWelcomeEmailAsTemplate (\AcceptanceTester $I) {
     $I->wantTo('Save welcome email as a template');
     $templateTitle = 'Welcome Template Test Title';
     $templateDescr = 'Welcome Template Test Descr';
diff --git a/tests/acceptance/NewsletterCreationCest.php b/tests/acceptance/NewsletterCreationCest.php
index ab54c41489..c4cf4645c1 100644
--- a/tests/acceptance/NewsletterCreationCest.php
+++ b/tests/acceptance/NewsletterCreationCest.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Acceptance;
 
 class NewsletterCreationCest {
 
-  function createPostNotification(\AcceptanceTester $I) {
+  public function createPostNotification(\AcceptanceTester $I) {
     $I->wantTo('Create and configure post notification email');
 
     $newsletter_title = 'Post Notification ' . \MailPoet\Util\Security::generateRandomString();
@@ -45,7 +45,7 @@ class NewsletterCreationCest {
     $I->see("Send immediately if there's new content to " . $segment_name . ".", $newsletter_listing_element);
   }
 
-  function createStandardNewsletter(\AcceptanceTester $I) {
+  public function createStandardNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Create and configure standard newsletter');
 
     $newsletter_title = 'Testing Newsletter ' . \MailPoet\Util\Security::generateRandomString();
diff --git a/tests/acceptance/NewsletterSendingErrorCest.php b/tests/acceptance/NewsletterSendingErrorCest.php
index 24b7aca92f..baf4196920 100644
--- a/tests/acceptance/NewsletterSendingErrorCest.php
+++ b/tests/acceptance/NewsletterSendingErrorCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 use MailPoet\Test\DataFactories\Settings;
 
 class NewsletterSendingErrorCest {
-  function generalErrorNotice(\AcceptanceTester $I) {
+  public function generalErrorNotice(\AcceptanceTester $I) {
     (new Newsletter())->create();
 
     $I->wantTo('See proper sending error when sending failed');
@@ -31,7 +31,7 @@ class NewsletterSendingErrorCest {
     $I->waitForText('Sending has been resumed.');
   }
 
-  function phpMailErrorNotice(\AcceptanceTester $I) {
+  public function phpMailErrorNotice(\AcceptanceTester $I) {
     (new Newsletter())->create();
 
     $I->wantTo('See proper sending error when sending failed with PHPMail');
diff --git a/tests/acceptance/NewsletterStatisticsCest.php b/tests/acceptance/NewsletterStatisticsCest.php
index b9b55cc7b2..6cc13c5e8f 100644
--- a/tests/acceptance/NewsletterStatisticsCest.php
+++ b/tests/acceptance/NewsletterStatisticsCest.php
@@ -19,13 +19,13 @@ class NewsletterStatisticsCest {
     $this->settings = $settings;
   }
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings->withWooCommerceListImportPageDisplayed(true);
     $this->settings->withCookieRevenueTrackingDisabled();
   }
 
-  function showWooCommercePurchaseStatistics(\AcceptanceTester $I) {
+  public function showWooCommercePurchaseStatistics(\AcceptanceTester $I) {
     $title = 'Newsletter Title';
     $currency = 'EUR';
     $I->cli(['option', 'set', 'woocommerce_currency', $currency]);
@@ -53,7 +53,7 @@ class NewsletterStatisticsCest {
     $I->see('5,00€', '.mailpoet_stats_text a');
   }
 
-  function dontShowWooCommercePurchaseStatisticsWithZeroValue(\AcceptanceTester $I) {
+  public function dontShowWooCommercePurchaseStatisticsWithZeroValue(\AcceptanceTester $I) {
     $title = 'Newsletter Title';
     $currency = 'EUR';
     $I->cli(['option', 'set', 'woocommerce_currency', $currency]);
diff --git a/tests/acceptance/NewslettersListingCest.php b/tests/acceptance/NewslettersListingCest.php
index d10dfc3ccb..0a4d361864 100644
--- a/tests/acceptance/NewslettersListingCest.php
+++ b/tests/acceptance/NewslettersListingCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class NewslettersListingCest {
 
-  function newslettersListing(\AcceptanceTester $I) {
+  public function newslettersListing(\AcceptanceTester $I) {
     $standard_newsletter_subject = 'Standard newsletter';
     $welcome_email_subject = 'Welcome email';
     $post_notification_email_subject = 'Post notification';
@@ -41,7 +41,7 @@ class NewslettersListingCest {
     $I->seeNoJSErrors();
   }
 
-  function statisticsColumn(\AcceptanceTester $I) {
+  public function statisticsColumn(\AcceptanceTester $I) {
     (new Newsletter())->create();
 
     $I->wantTo('Check if statistics column is visible depending on tracking option');
diff --git a/tests/acceptance/PreviewPostNotificationNewsletterCest.php b/tests/acceptance/PreviewPostNotificationNewsletterCest.php
index a8531fdd47..3b20a356d9 100644
--- a/tests/acceptance/PreviewPostNotificationNewsletterCest.php
+++ b/tests/acceptance/PreviewPostNotificationNewsletterCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\Newsletter;
 
 class PreviewPostNotificationNewsletterCest {
-  function previewStandardNewsletter(\AcceptanceTester $I) {
+  public function previewStandardNewsletter(\AcceptanceTester $I) {
     $newsletterName = 'Preview in Browser Post Notification';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletterName)->withPostNotificationsType()->create();
diff --git a/tests/acceptance/PreviewStandardNewsletterCest.php b/tests/acceptance/PreviewStandardNewsletterCest.php
index 25ea16c258..af978ae8d8 100644
--- a/tests/acceptance/PreviewStandardNewsletterCest.php
+++ b/tests/acceptance/PreviewStandardNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class PreviewStandardNewsletterCest {
 
-  function previewStandardNewsletter(\AcceptanceTester $I) {
+  public function previewStandardNewsletter(\AcceptanceTester $I) {
     $newsletterName = 'Preview in Browser Newsletter';
     $newsletter = new Newsletter();
     $newsletter->withSubject($newsletterName)->create();
diff --git a/tests/acceptance/ReceivePostNotificationCest.php b/tests/acceptance/ReceivePostNotificationCest.php
index a3204b8340..39016b9466 100644
--- a/tests/acceptance/ReceivePostNotificationCest.php
+++ b/tests/acceptance/ReceivePostNotificationCest.php
@@ -19,7 +19,7 @@ class ReceivePostNotificationCest {
     $this->settings = $settings;
   }
 
-  function receivePostNotification(\AcceptanceTester $I) {
+  public function receivePostNotification(\AcceptanceTester $I) {
     $I->wantTo('Receive a post notification email');
     $newsletter_subject = 'Post Notification Receive Test' . \MailPoet\Util\Security::generateRandomString();
     $post_title = 'A post ' . \MailPoet\Util\Security::generateRandomString();
diff --git a/tests/acceptance/ReceiveStandardEmailCest.php b/tests/acceptance/ReceiveStandardEmailCest.php
index 54a7bfc3eb..93b7bfc5f1 100644
--- a/tests/acceptance/ReceiveStandardEmailCest.php
+++ b/tests/acceptance/ReceiveStandardEmailCest.php
@@ -14,7 +14,7 @@ class ReceiveStandardEmailCest {
     $this->settings = $settings;
   }
 
-  function receiveStandardEmail(\AcceptanceTester $I) {
+  public function receiveStandardEmail(\AcceptanceTester $I) {
     $this->settings->withCronTriggerMethod('WordPress');
 
     // try some special characters in the subject to ensure they are received correctly
diff --git a/tests/acceptance/ReinstallFromScratchCest.php b/tests/acceptance/ReinstallFromScratchCest.php
index 58292fae63..4771b1752e 100644
--- a/tests/acceptance/ReinstallFromScratchCest.php
+++ b/tests/acceptance/ReinstallFromScratchCest.php
@@ -11,7 +11,7 @@ use PHPUnit_Framework_Assert as Asserts;
 
 class ReinstallFromScratchCest {
 
-  function reinstallFromScratch(\AcceptanceTester $I) {
+  public function reinstallFromScratch(\AcceptanceTester $I) {
     $I->wantTo('Reinstall from scratch');
     $I->login();
 
diff --git a/tests/acceptance/RestoreTrashedSegmentCest.php b/tests/acceptance/RestoreTrashedSegmentCest.php
index a9ba54e4f8..b5078e4ccc 100644
--- a/tests/acceptance/RestoreTrashedSegmentCest.php
+++ b/tests/acceptance/RestoreTrashedSegmentCest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Acceptance;
 use MailPoet\Test\DataFactories\DynamicSegment;
 
 class RestoreTrashedSegmentCest {
-  function restoreSegmentFromTrash(\AcceptanceTester $I) {
+  public function restoreSegmentFromTrash(\AcceptanceTester $I) {
     $I->wantTo('Restore a segment from trash');
 
     $segment_title = 'Restore Segment From Trash Test';
diff --git a/tests/acceptance/RevenueTrackingCookieCest.php b/tests/acceptance/RevenueTrackingCookieCest.php
index b5fdb64361..1237de9989 100644
--- a/tests/acceptance/RevenueTrackingCookieCest.php
+++ b/tests/acceptance/RevenueTrackingCookieCest.php
@@ -15,12 +15,12 @@ class RevenueTrackingCookieCest {
     $this->settings = $settings;
   }
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings->withCronTriggerMethod('WordPress');
   }
 
-  function cookieIsStoredOnClick(\AcceptanceTester $I) {
+  public function cookieIsStoredOnClick(\AcceptanceTester $I) {
     $I->wantTo('Test Revenue cookie is saved');
     $newsletter_subject = 'Receive Test' . \MailPoet\Util\Security::generateRandomString();
     $newsletter = (new Newsletter())->withSubject($newsletter_subject)->create();
@@ -59,7 +59,7 @@ class RevenueTrackingCookieCest {
     $I->canSeeCookie('mailpoet_revenue_tracking');
   }
 
-  function cookieIsNotStoredWhenSettingsDisabled(\AcceptanceTester $I) {
+  public function cookieIsNotStoredWhenSettingsDisabled(\AcceptanceTester $I) {
     $I->wantTo('Test Revenue cookie is not saved');
     $newsletter_subject = 'Receive Test' . \MailPoet\Util\Security::generateRandomString();
     $newsletter = (new Newsletter())->withSubject($newsletter_subject)->create();
diff --git a/tests/acceptance/SaveNewsletterAsDraftCest.php b/tests/acceptance/SaveNewsletterAsDraftCest.php
index 5cf43f6875..deeacc7584 100644
--- a/tests/acceptance/SaveNewsletterAsDraftCest.php
+++ b/tests/acceptance/SaveNewsletterAsDraftCest.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Acceptance;
 
 class SaveNewsletterAsDraftCest {
 
-  function saveStandardNewsletterAsDraft(\AcceptanceTester $I) {
+  public function saveStandardNewsletterAsDraft(\AcceptanceTester $I) {
     $I->wantTo('Create standard newsletter and save as a draft');
 
     $newsletter_title = 'Testing Newsletter ' . \MailPoet\Util\Security::generateRandomString();
diff --git a/tests/acceptance/SaveNewsletterAsTemplateCest.php b/tests/acceptance/SaveNewsletterAsTemplateCest.php
index c7fe6333b9..7bea0d078d 100644
--- a/tests/acceptance/SaveNewsletterAsTemplateCest.php
+++ b/tests/acceptance/SaveNewsletterAsTemplateCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SaveNewsletterAsTemplateCest {
 
-  function saveStandardNewsletterAsTemplate(\AcceptanceTester $I) {
+  public function saveStandardNewsletterAsTemplate(\AcceptanceTester $I) {
     $I->wantTo('Create standard newsletter and save as a template');
 
     $newsletter_title = 'Testing Templates ' . \MailPoet\Util\Security::generateRandomString();
diff --git a/tests/acceptance/SaveNotificationAsDraftCest.php b/tests/acceptance/SaveNotificationAsDraftCest.php
index bec52e5ca3..c9e5db5312 100644
--- a/tests/acceptance/SaveNotificationAsDraftCest.php
+++ b/tests/acceptance/SaveNotificationAsDraftCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SaveNotificationAsDraftCest {
 
-  function saveNotificationAsDraft(\AcceptanceTester $I) {
+  public function saveNotificationAsDraft(\AcceptanceTester $I) {
     // step 1 - Prepare post notification data
     $I->wantTo('Save post notification email as draft');
     $newsletter_title = 'Draft Test Post Notification';
diff --git a/tests/acceptance/SavePostNotificationEmailAsTemplateCest.php b/tests/acceptance/SavePostNotificationEmailAsTemplateCest.php
index 7aa2274cbb..71e5252bab 100644
--- a/tests/acceptance/SavePostNotificationEmailAsTemplateCest.php
+++ b/tests/acceptance/SavePostNotificationEmailAsTemplateCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SavePostNotificationEmailAsTemplateCest {
 
-  function saveAsTemplate(\AcceptanceTester $I) {
+  public function saveAsTemplate(\AcceptanceTester $I) {
     $I->wantTo('Save post notification email as template');
 
     $newsletter_title = 'Template Test Post Notification';
diff --git a/tests/acceptance/ScheduleNewsletterCest.php b/tests/acceptance/ScheduleNewsletterCest.php
index 701c1fb27e..e00b386d02 100644
--- a/tests/acceptance/ScheduleNewsletterCest.php
+++ b/tests/acceptance/ScheduleNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class ScheduleNewsletterCest {
 
-  function scheduleStandardNewsletter(\AcceptanceTester $I) {
+  public function scheduleStandardNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Schedule a newsletter');
     $newsletter_title = 'Schedule Test Newsletter';
 
diff --git a/tests/acceptance/SearchForNotificationCest.php b/tests/acceptance/SearchForNotificationCest.php
index cab6d1642c..8f9242215f 100644
--- a/tests/acceptance/SearchForNotificationCest.php
+++ b/tests/acceptance/SearchForNotificationCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SearchForNotificationCest {
 
-  function searchForStandardNotification(\AcceptanceTester $I) {
+  public function searchForStandardNotification(\AcceptanceTester $I) {
     $I->wantTo('Successfully search for an existing notification');
     $newsletter_title = 'Search Test Notification';
     $failure_condition_newsletter = 'Not Actually Real';
diff --git a/tests/acceptance/SearchForStandardNewsletterCest.php b/tests/acceptance/SearchForStandardNewsletterCest.php
index d9c8ea2274..500eed4b39 100644
--- a/tests/acceptance/SearchForStandardNewsletterCest.php
+++ b/tests/acceptance/SearchForStandardNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SearchForStandardNewsletterCest {
 
-  function searchForStandardNewsletter(\AcceptanceTester $I) {
+  public function searchForStandardNewsletter(\AcceptanceTester $I) {
     $I->wantTo('Successfully search for an existing newsletter');
 
     $newsletter_title = 'Search Test Newsletter';
diff --git a/tests/acceptance/SendCategoryPurchaseEmailCest.php b/tests/acceptance/SendCategoryPurchaseEmailCest.php
index 8afb11e085..ad2287c293 100644
--- a/tests/acceptance/SendCategoryPurchaseEmailCest.php
+++ b/tests/acceptance/SendCategoryPurchaseEmailCest.php
@@ -10,7 +10,7 @@ use MailPoet\Util\Security;
 
 class SendCategoryPurchaseEmailCest {
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $settings_factory = new Settings();
     $settings_factory->withWooCommerceListImportPageDisplayed(true);
@@ -18,7 +18,7 @@ class SendCategoryPurchaseEmailCest {
     $settings_factory->withCronTriggerMethod('WordPress');
   }
 
-  function sendCategoryPurchaseEmail(\AcceptanceTester $I) {
+  public function sendCategoryPurchaseEmail(\AcceptanceTester $I) {
     $I->wantTo('Buy a product in category and receive a "Purchased In This Category" email');
 
     $product_name = 'Category Purchase Test Product';
diff --git a/tests/acceptance/SendFirstPurchaseEmailCest.php b/tests/acceptance/SendFirstPurchaseEmailCest.php
index 1db33922d5..5c87a8471a 100644
--- a/tests/acceptance/SendFirstPurchaseEmailCest.php
+++ b/tests/acceptance/SendFirstPurchaseEmailCest.php
@@ -11,7 +11,7 @@ class SendFirstPurchaseEmailCest {
   /** @var Settings */
   private $settings_factory;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings_factory = new Settings();
     $this->settings_factory->withWooCommerceListImportPageDisplayed(true);
@@ -19,7 +19,7 @@ class SendFirstPurchaseEmailCest {
     $this->settings_factory->withCronTriggerMethod('WordPress');
   }
 
-  function sendFirstPurchaseEmail(\AcceptanceTester $I) {
+  public function sendFirstPurchaseEmail(\AcceptanceTester $I) {
     $I->wantTo('Send a "First purchase email"');
 
     $product_name = 'First Purchase Product';
@@ -43,7 +43,7 @@ class SendFirstPurchaseEmailCest {
     $I->waitForText($user_email, 20);
   }
 
-  function doNotSendFirstPurchaseEmailIfUserHasNotOptedIn(\AcceptanceTester $I) {
+  public function doNotSendFirstPurchaseEmailIfUserHasNotOptedIn(\AcceptanceTester $I) {
     $I->wantTo('Buy a product, do not opt-in and don\'t receive a "First purchase email"');
 
     $product_name = 'First Purchase Product';
diff --git a/tests/acceptance/SendProductPurchaseEmailCest.php b/tests/acceptance/SendProductPurchaseEmailCest.php
index 4f57b2d13f..26af9c16a7 100644
--- a/tests/acceptance/SendProductPurchaseEmailCest.php
+++ b/tests/acceptance/SendProductPurchaseEmailCest.php
@@ -11,7 +11,7 @@ class SendProductPurchaseEmailCest {
   /** @var Settings */
   private $settings_factory;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings_factory = new Settings();
     $this->settings_factory->withWooCommerceListImportPageDisplayed(true);
@@ -19,7 +19,7 @@ class SendProductPurchaseEmailCest {
     $this->settings_factory->withCronTriggerMethod('WordPress');
   }
 
-  function sendProductPurchaseEmail(\AcceptanceTester $I) {
+  public function sendProductPurchaseEmail(\AcceptanceTester $I) {
     $I->wantTo('Buy a product and receive a "Product Purchase" email');
 
     $product_name = 'Product Purchase Test Product';
@@ -43,7 +43,7 @@ class SendProductPurchaseEmailCest {
     $I->waitForText($user_email, 20);
   }
 
-  function doNotSendProductPurchaseEmailIfUserHasNotOptedIn(\AcceptanceTester $I) {
+  public function doNotSendProductPurchaseEmailIfUserHasNotOptedIn(\AcceptanceTester $I) {
     $I->wantTo('Buy a product, do not opt-in and don\'t receive a "Product Purchase" email');
 
     $product_name = 'Product Purchase Test Product';
diff --git a/tests/acceptance/SendingStatusCest.php b/tests/acceptance/SendingStatusCest.php
index b852e7316b..d551c13acd 100644
--- a/tests/acceptance/SendingStatusCest.php
+++ b/tests/acceptance/SendingStatusCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 use MailPoet\Test\DataFactories\Subscriber;
 
 class SendingStatusCest {
-  function newsletterSendingStatus(\AcceptanceTester $I) {
+  public function newsletterSendingStatus(\AcceptanceTester $I) {
     $I->wantTo('Check the sending status page for a standard newsletter');
     // Having a standard newsletter sent to 2 subscribers
     $lucky_subscriber = (new Subscriber)
diff --git a/tests/acceptance/SentNewsletterCest.php b/tests/acceptance/SentNewsletterCest.php
index 1fcc6a896b..8c7b7efcea 100644
--- a/tests/acceptance/SentNewsletterCest.php
+++ b/tests/acceptance/SentNewsletterCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class SentNewsletterCest {
 
-  function disableLastStep(\AcceptanceTester $I) {
+  public function disableLastStep(\AcceptanceTester $I) {
     $I->wantTo('See that last step is disabled fot sent standard email');
 
     $newsletter = (new Newsletter())
diff --git a/tests/acceptance/SettingsArchivePageCest.php b/tests/acceptance/SettingsArchivePageCest.php
index fb05ab1dc8..163e319715 100644
--- a/tests/acceptance/SettingsArchivePageCest.php
+++ b/tests/acceptance/SettingsArchivePageCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 use MailPoet\Test\DataFactories\Segment;
 
 class SettingsArchivePageCest {
-  function createArchivePageNoSentNewsletters(\AcceptanceTester $I) {
+  public function createArchivePageNoSentNewsletters(\AcceptanceTester $I) {
     $I->wantTo('Create page with MP archive shortcode, showing no sent newsletters');
     $segment_factory = new Segment();
     $segment = $segment_factory->withName('Empty Send')->create();
@@ -22,7 +22,7 @@ class SettingsArchivePageCest {
     $I->waitForText($pageTitle);
     $I->waitForText('Oops! There are no newsletters to display.');
   }
-  function createArchivePageWithSentNewsletters(\AcceptanceTester $I) {
+  public function createArchivePageWithSentNewsletters(\AcceptanceTester $I) {
     $I->wantTo('Create page with MP archive shortcode, showing sent newsletters');
     $segment_factory = new Segment();
     $segment2 = $segment_factory->withName('SentNewsletters')->create();
diff --git a/tests/acceptance/SettingsFreeEmailAsFromAddressTriggersAlertCest.php b/tests/acceptance/SettingsFreeEmailAsFromAddressTriggersAlertCest.php
index e2a720315f..2342a599f8 100644
--- a/tests/acceptance/SettingsFreeEmailAsFromAddressTriggersAlertCest.php
+++ b/tests/acceptance/SettingsFreeEmailAsFromAddressTriggersAlertCest.php
@@ -6,7 +6,7 @@ use MailPoet\Mailer\Mailer;
 use MailPoet\Test\DataFactories\Settings;
 
 class SettingsFreeEmailAsFromAddressTriggersAlertCest {
-  function addFreeEmailAsFromAddressWithMSS(\AcceptanceTester $I) {
+  public function addFreeEmailAsFromAddressWithMSS(\AcceptanceTester $I) {
     $I->wantTo('Confirm free emails as FROM address does not trigger alert message when sending with MSS');
     $settings = new Settings();
     $settings->withSendingMethodMailPoet();
@@ -23,7 +23,7 @@ class SettingsFreeEmailAsFromAddressTriggersAlertCest {
     $I->dontSeeElement('.sender_email_address_warning');
   }
 
-  function addFreeEmailAsFromAddressWithoutMSS(\AcceptanceTester $I) {
+  public function addFreeEmailAsFromAddressWithoutMSS(\AcceptanceTester $I) {
     $I->wantTo('Confirm free emails as FROM address trigger alert message when sending without MSS');
     $settings = new Settings();
     $settings->withSendingMethod(Mailer::METHOD_PHPMAIL);
diff --git a/tests/acceptance/SettingsInactiveSubscribersChangeCest.php b/tests/acceptance/SettingsInactiveSubscribersChangeCest.php
index 01e99ae37b..bd270da32d 100644
--- a/tests/acceptance/SettingsInactiveSubscribersChangeCest.php
+++ b/tests/acceptance/SettingsInactiveSubscribersChangeCest.php
@@ -31,7 +31,7 @@ class SettingsInactiveSubscribersChangeCest {
       ->withCronTriggerMethod('WordPress');
   }
 
-  function inactiveSubscribersSettingsChange(\AcceptanceTester $I) {
+  public function inactiveSubscribersSettingsChange(\AcceptanceTester $I) {
     $I->wantTo('Change inactive users settings and reactivate all subscribers');
     $I->login();
     $I->amOnMailPoetPage('Settings');
diff --git a/tests/acceptance/SettingsPageBasicsCest.php b/tests/acceptance/SettingsPageBasicsCest.php
index 6d523c302d..b35748cb96 100644
--- a/tests/acceptance/SettingsPageBasicsCest.php
+++ b/tests/acceptance/SettingsPageBasicsCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Settings;
 
 class SettingsPageBasicsCest {
 
-  function checkSettingsPagesLoad(\AcceptanceTester $I) {
+  public function checkSettingsPagesLoad(\AcceptanceTester $I) {
     $I->wantTo('Confirm all settings pages load correctly');
     $I->login();
     $I->amOnMailPoetPage('Settings');
@@ -32,7 +32,7 @@ class SettingsPageBasicsCest {
     $I->seeNoJSErrors();
   }
 
-  function editDefaultSenderInformation(\AcceptanceTester $I) {
+  public function editDefaultSenderInformation(\AcceptanceTester $I) {
     $I->wantTo('Confirm default sender information can be edited');
     $I->login();
     $I->amOnMailPoetPage('Settings');
@@ -45,7 +45,7 @@ class SettingsPageBasicsCest {
     $I->waitForText('Settings saved');
   }
 
-  function allowSubscribeInComments(\AcceptanceTester $I) {
+  public function allowSubscribeInComments(\AcceptanceTester $I) {
     $I->wantTo('Allow users to subscribe to lists in site comments');
     $post_title = 'Hello world!';
     $I->login();
@@ -71,7 +71,7 @@ class SettingsPageBasicsCest {
     $I->dontSee("Yes, add me to your mailing list");
   }
 
-  function checkSenderFreemailWarning(\AcceptanceTester $I) {
+  public function checkSenderFreemailWarning(\AcceptanceTester $I) {
     $settings = new Settings();
     $settings->withSendingMethod(Mailer::METHOD_SMTP);
     $settings->withTodayInstallationDate();
diff --git a/tests/acceptance/SettingsSubscriptionPageCest.php b/tests/acceptance/SettingsSubscriptionPageCest.php
index 9604bac1ed..da5e02d1f4 100644
--- a/tests/acceptance/SettingsSubscriptionPageCest.php
+++ b/tests/acceptance/SettingsSubscriptionPageCest.php
@@ -3,14 +3,14 @@
 namespace MailPoet\Test\Acceptance;
 
 class SettingsSubscriptionPageCest {
-  function previewDefaultSubscriptionPage(\AcceptanceTester $I) {
+  public function previewDefaultSubscriptionPage(\AcceptanceTester $I) {
     $I->wantTo('Preview default MailPoet page from MP Settings page');
     $I->login();
     $I->amOnMailPoetPage('Settings');
     $I->click('[data-automation-id="preview_manage_subscription_page_link"]');
     $I->waitForText('Manage your subscription');
   }
-  function createNewSubscriptionPage(\AcceptanceTester $I) {
+  public function createNewSubscriptionPage(\AcceptanceTester $I) {
     $I->wantTo('Make a custom subscription page');
     $page_title = 'CustomSubscriptionPage';
     $page_content = '[mailpoet_manage_subscription]';
diff --git a/tests/acceptance/SettingsUnsubscribePageCest.php b/tests/acceptance/SettingsUnsubscribePageCest.php
index b6f6cc1052..62070e8c22 100644
--- a/tests/acceptance/SettingsUnsubscribePageCest.php
+++ b/tests/acceptance/SettingsUnsubscribePageCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class SettingsUnsubscribePageCest {
-  function previvewDefaultUnsubscribePage(\AcceptanceTester $I) {
+  public function previvewDefaultUnsubscribePage(\AcceptanceTester $I) {
     $I->wantTo('Preview default MailPoet Unsubscribe page from MP Settings page');
     $I->login();
     $I->amOnMailPoetPage('Settings');
diff --git a/tests/acceptance/StatsPageCest.php b/tests/acceptance/StatsPageCest.php
index 07560fdaaf..478665cd32 100644
--- a/tests/acceptance/StatsPageCest.php
+++ b/tests/acceptance/StatsPageCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Newsletter;
 
 class StatsPageCest {
 
-  function statsPage(\AcceptanceTester $I) {
+  public function statsPage(\AcceptanceTester $I) {
     $I->wantTo('Open stats page of a sent newsletter');
 
     $newsletter_title = 'Stats Page Test';
diff --git a/tests/acceptance/SubscribeOnRegistrationPageCest.php b/tests/acceptance/SubscribeOnRegistrationPageCest.php
index dbeacc7faf..46a8c33f44 100644
--- a/tests/acceptance/SubscribeOnRegistrationPageCest.php
+++ b/tests/acceptance/SubscribeOnRegistrationPageCest.php
@@ -6,7 +6,7 @@ use Codeception\Util\Locator;
 use MailPoet\Test\DataFactories\Segment;
 
 class SubscribeOnRegistrationPageCest {
-  function allowSubscribeOnRegistrationPage(\AcceptanceTester $I) {
+  public function allowSubscribeOnRegistrationPage(\AcceptanceTester $I) {
     $I->wantTo('Allow users to subscribe to lists on site registration page');
     //create a list for this test
     $segment_factory = new Segment();
@@ -44,7 +44,7 @@ class SubscribeOnRegistrationPageCest {
     $I->waitForText($regseg);
   }
 
-  function sendConfirmationEmailOnRegistration(\AcceptanceTester $I) {
+  public function sendConfirmationEmailOnRegistration(\AcceptanceTester $I) {
     $I->wantTo('send confirmation email on user registration when no additional lists');
     $user_email = 'registerpagesignupconfirmation@fake.fake';
     $I->login();
diff --git a/tests/acceptance/SubscribeToMultipleListsCest.php b/tests/acceptance/SubscribeToMultipleListsCest.php
index e98a747ddc..c1be72d064 100644
--- a/tests/acceptance/SubscribeToMultipleListsCest.php
+++ b/tests/acceptance/SubscribeToMultipleListsCest.php
@@ -9,7 +9,7 @@ use MailPoet\Test\DataFactories\Settings;
 
 class SubscribeToMultipleListsCest {
 
-  function subscribeToMultipleLists(\AcceptanceTester $I) {
+  public function subscribeToMultipleLists(\AcceptanceTester $I) {
     //Step one - create form with three lists
     $segment_factory = new Segment();
     $seg1 = 'Cats';
diff --git a/tests/acceptance/SubscriberCountShortcodeCest.php b/tests/acceptance/SubscriberCountShortcodeCest.php
index 8bf6a47c9a..27bd492f3d 100644
--- a/tests/acceptance/SubscriberCountShortcodeCest.php
+++ b/tests/acceptance/SubscriberCountShortcodeCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Segment;
 use MailPoet\Test\DataFactories\Subscriber;
 
 class SubscriberCountShortcodeCest {
-  function createSubscriberCountPageWithShortcode(\AcceptanceTester $I) {
+  public function createSubscriberCountPageWithShortcode(\AcceptanceTester $I) {
     $I->wantTo('Create page with MP subscriber shortcode');
     $segment_factory = new Segment();
     $segment = $segment_factory->withName('SubscriberCount')->create();
diff --git a/tests/acceptance/SubscriberManageImportExportCest.php b/tests/acceptance/SubscriberManageImportExportCest.php
index 2822f3ebb4..1540704783 100644
--- a/tests/acceptance/SubscriberManageImportExportCest.php
+++ b/tests/acceptance/SubscriberManageImportExportCest.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Acceptance;
 
 class SubscriberManageImportExportCest {
 
-  function importBigUsersListCSV(\AcceptanceTester $I) {
+  public function importBigUsersListCSV(\AcceptanceTester $I) {
     $I->wantTo('Import a big list');
     $I->login();
     $I->amOnUrl(\AcceptanceTester::WP_URL . '/wp-admin/admin.php?page=mailpoet-import');
@@ -39,7 +39,7 @@ class SubscriberManageImportExportCest {
     $I->waitForElement('[data-automation-id="import_data_manipulation_step"]');
   }
 
-  function importUsersToSubscribersViaCSV(\AcceptanceTester $I) {
+  public function importUsersToSubscribersViaCSV(\AcceptanceTester $I) {
     $I->wantTo('Import a subscriber list from CSV');
     $I->login();
     $I->amOnMailPoetPage ('Subscribers');
diff --git a/tests/acceptance/SubscriberManagementCest.php b/tests/acceptance/SubscriberManagementCest.php
index 221be4c8cf..baedd2b8a6 100644
--- a/tests/acceptance/SubscriberManagementCest.php
+++ b/tests/acceptance/SubscriberManagementCest.php
@@ -53,7 +53,7 @@ class SubscriberManagementCest {
     }
   }
 
-  function viewSubscriberList(\AcceptanceTester $I) {
+  public function viewSubscriberList(\AcceptanceTester $I) {
     $I->wantTo('View list of subscribers');
     $this->generateWPUsersList($I);
     $I->searchFor('Alec Saunders');
@@ -61,7 +61,7 @@ class SubscriberManagementCest {
     $I->seeNoJSErrors();
   }
 
-  function addGlobalSubscriber(\AcceptanceTester $I) {
+  public function addGlobalSubscriber(\AcceptanceTester $I) {
     $I->wantTo('Add a user to global subscribers list');
     $I->login();
     $I->amOnMailPoetPage ('Subscribers');
@@ -77,7 +77,7 @@ class SubscriberManagementCest {
     $I->seeNoJSErrors();
   }
 
-  function deleteGlobalSubscriber(\AcceptanceTester $I) {
+  public function deleteGlobalSubscriber(\AcceptanceTester $I) {
     $I->wantTo('Delete a user from global subscribers list');
     $new_subscriber_email = 'deleteglobaluser99@fakemail.fake';
     $this->generateSingleSubscriber('deleteglobaluser99@fakemail.fake', 'Delete', 'ThisGlobalUser');
@@ -94,7 +94,7 @@ class SubscriberManagementCest {
     $I->seeNoJSErrors();
   }
 
-  function addSubscriberToList(\AcceptanceTester $I) {
+  public function addSubscriberToList(\AcceptanceTester $I) {
     $I->wantTo('Add a subscriber to a list');
     $new_subscriber_email = 'addtolistuser99@fakemail.fake';
     $this->generateMultipleLists();
@@ -110,7 +110,7 @@ class SubscriberManagementCest {
     $I->seeNoJSErrors();
   }
 
-  function deleteSubscriberFromList(\AcceptanceTester $I) {
+  public function deleteSubscriberFromList(\AcceptanceTester $I) {
     $I->wantTo('Delete a subscriber from a list');
     $new_subscriber_email = 'deletefromlistuser99@fakemail.fake';
     $this->generateMultipleLists();
@@ -127,7 +127,7 @@ class SubscriberManagementCest {
     $I->waitForText('Subscriber was updated');
   }
 
-  function editSubscriber(\AcceptanceTester $I) {
+  public function editSubscriber(\AcceptanceTester $I) {
     $I->wantTo('Edit a subscriber');
     $new_subscriber_email = 'editglobaluser99@fakemail.fake';
     $this->generateSingleSubscriber('editglobaluser99@fakemail.fake', 'Edit', 'ThisGlobalUser');
@@ -138,7 +138,7 @@ class SubscriberManagementCest {
     $I->waitForText('Subscriber');
   }
 
-  function inactiveSubscribers(\AcceptanceTester $I) {
+  public function inactiveSubscribers(\AcceptanceTester $I) {
     $I->wantTo('Check inactive subscribers');
     $this->prepareInactiveSubscribersData();
     $I->login();
diff --git a/tests/acceptance/SubscribersListingCest.php b/tests/acceptance/SubscribersListingCest.php
index 434b28ed0c..b982b7eb88 100644
--- a/tests/acceptance/SubscribersListingCest.php
+++ b/tests/acceptance/SubscribersListingCest.php
@@ -7,7 +7,7 @@ use MailPoet\Test\DataFactories\Subscriber;
 
 class SubscribersListingCest {
 
-  function subscribersListing(\AcceptanceTester $I) {
+  public function subscribersListing(\AcceptanceTester $I) {
     $I->wantTo('Open subscribers listings page');
 
     (new Subscriber())
@@ -20,7 +20,7 @@ class SubscribersListingCest {
     $I->waitForText('wp@example.com');
   }
 
-  function sendConfirmationEmail(\AcceptanceTester $I) {
+  public function sendConfirmationEmail(\AcceptanceTester $I) {
     $I->wantTo('Send confirmation email');
 
     $disallowed_email = 'disallowed@example.com';
diff --git a/tests/acceptance/SubscriptionCaptchaCest.php b/tests/acceptance/SubscriptionCaptchaCest.php
index 21ee02f377..4cb44df124 100644
--- a/tests/acceptance/SubscriptionCaptchaCest.php
+++ b/tests/acceptance/SubscriptionCaptchaCest.php
@@ -15,7 +15,7 @@ class SubscriptionCaptchaCest {
   /** @var string */
   private $subscriber_email;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $this->subscriber_email = 'test-form@example.com';
     $this->settings_factory = new Settings();
     $this->settings_factory->withCaptchaType(Captcha::TYPE_BUILTIN);
@@ -34,7 +34,7 @@ class SubscriptionCaptchaCest {
     $I->cli(['widget', 'add', 'mailpoet_form', 'sidebar-1', '2', "--form=$form->id", '--title=Subscribe to Our Newsletter']);
   }
 
-  function checkCaptchaPageExistsAfterSubscription(\AcceptanceTester $I) {
+  public function checkCaptchaPageExistsAfterSubscription(\AcceptanceTester $I) {
     $I->wantTo('See the built-in captcha after subscribing using form widget');
     $I->amOnPage('/');
     $I->fillField('[data-automation-id="form_email"]', $this->subscriber_email);
@@ -43,7 +43,7 @@ class SubscriptionCaptchaCest {
     $I->seeNoJSErrors();
   }
 
-  function checkCaptchaPageIsNotShownToLoggedInUsers(\AcceptanceTester $I) {
+  public function checkCaptchaPageIsNotShownToLoggedInUsers(\AcceptanceTester $I) {
     $I->wantTo('check that captcha page is not shown to logged in users');
     $I->login();
     $I->amOnPage('/');
diff --git a/tests/acceptance/SubscriptionFormCest.php b/tests/acceptance/SubscriptionFormCest.php
index a0e572b54f..0b7a1b9bc8 100644
--- a/tests/acceptance/SubscriptionFormCest.php
+++ b/tests/acceptance/SubscriptionFormCest.php
@@ -13,11 +13,11 @@ class SubscriptionFormCest {
   /** @var string */
   private $subscriber_email;
 
-  function __construct() {
+  public function __construct() {
     $this->subscriber_email = 'test-form@example.com';
   }
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $settings = new Settings();
     $settings
       ->withConfirmationEmailSubject()
@@ -39,7 +39,7 @@ class SubscriptionFormCest {
     ]);
   }
 
-  function subscriptionFormWidget(\AcceptanceTester $I) {
+  public function subscriptionFormWidget(\AcceptanceTester $I) {
     $form_name = 'Subscription Acceptance Test Form';
     $form_factory = new Form();
     $form = $form_factory->withName($form_name)->create();
@@ -55,7 +55,7 @@ class SubscriptionFormCest {
     $I->seeNoJSErrors();
   }
 
-  function subscriptionFormShortcode(\AcceptanceTester $I) {
+  public function subscriptionFormShortcode(\AcceptanceTester $I) {
     $I->wantTo('Subscribe using form shortcode');
 
     $I->amOnPage('/form-test');
@@ -67,7 +67,7 @@ class SubscriptionFormCest {
     $I->seeCurrentUrlEquals('/form-test/');
   }
 
-  function subscriptionFormIframe(\AcceptanceTester $I) {
+  public function subscriptionFormIframe(\AcceptanceTester $I) {
     $I->wantTo('Subscribe using iframe form');
 
     $I->amOnPage('/form-test');
@@ -81,7 +81,7 @@ class SubscriptionFormCest {
   /**
    * @depends subscriptionFormWidget
    */
-  function subscriptionConfirmation(\AcceptanceTester $I) {
+  public function subscriptionConfirmation(\AcceptanceTester $I) {
     $I->amOnPage('/form-test');
     $I->fillField('[data-automation-id="form_email"]', $this->subscriber_email);
     $I->scrollTo('.mailpoet_submit');
@@ -104,7 +104,7 @@ class SubscriptionFormCest {
     $I->see('Subscribed', Locator::contains('tr', $this->subscriber_email));
   }
 
-  function subscriptionAfterDisablingConfirmation(\AcceptanceTester $I) {
+  public function subscriptionAfterDisablingConfirmation(\AcceptanceTester $I) {
     $I->wantTo('Disable sign-up confirmation then subscribe and see a different message');
     $I->login();
     $I->amOnMailPoetPage('Settings');
diff --git a/tests/acceptance/SubscriptionFormEditCest.php b/tests/acceptance/SubscriptionFormEditCest.php
index 5376aeb9bd..f1faf05b87 100644
--- a/tests/acceptance/SubscriptionFormEditCest.php
+++ b/tests/acceptance/SubscriptionFormEditCest.php
@@ -6,7 +6,7 @@ use MailPoet\Test\DataFactories\Form;
 
 class SubscriptionFormEditCest {
 
-  function editForm(\AcceptanceTester $I) {
+  public function editForm(\AcceptanceTester $I) {
 
     //Step one - create form from factory
     $form_name = 'Testing Form Edit';
diff --git a/tests/acceptance/TemplatesPagesLoadCest.php b/tests/acceptance/TemplatesPagesLoadCest.php
index 31bde39d3e..372256dad3 100644
--- a/tests/acceptance/TemplatesPagesLoadCest.php
+++ b/tests/acceptance/TemplatesPagesLoadCest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Acceptance;
 
 class TemplatesPagesLoadCest {
-  function loadTemplatesPage(\AcceptanceTester $I) {
+  public function loadTemplatesPage(\AcceptanceTester $I) {
     $I->wantTo('Confirm template page loads and tabs can be clicked through');
     $I->login();
     $I->activateWooCommerce();
diff --git a/tests/acceptance/TrashExistingSegmentCest.php b/tests/acceptance/TrashExistingSegmentCest.php
index 624620cddf..cc8b3ff575 100644
--- a/tests/acceptance/TrashExistingSegmentCest.php
+++ b/tests/acceptance/TrashExistingSegmentCest.php
@@ -7,12 +7,12 @@ use MailPoet\Test\DataFactories\Settings;
 
 class TrashExistingSegmentCest {
 
-  function _before() {
+  public function _before() {
     (new Settings())->withWooCommerceListImportPageDisplayed(true);
     (new Settings())->withCookieRevenueTrackingDisabled();
   }
 
-  function moveSegmentToTrash(\AcceptanceTester $I) {
+  public function moveSegmentToTrash(\AcceptanceTester $I) {
     $I->wantTo('Move an existing segment to trash');
 
     $segment_title = 'Move Segment To Trash Test';
diff --git a/tests/acceptance/ViewSegmentSubscribersCest.php b/tests/acceptance/ViewSegmentSubscribersCest.php
index 1f8ee580b3..5916b350f4 100644
--- a/tests/acceptance/ViewSegmentSubscribersCest.php
+++ b/tests/acceptance/ViewSegmentSubscribersCest.php
@@ -7,12 +7,12 @@ use MailPoet\Test\DataFactories\Settings;
 
 class ViewSegmentSubscribersCest {
 
-  function _before() {
+  public function _before() {
     (new Settings())->withWooCommerceListImportPageDisplayed(true);
     (new Settings())->withCookieRevenueTrackingDisabled();
   }
 
-  function viewUserRoleSegmentSubscribers(\AcceptanceTester $I) {
+  public function viewUserRoleSegmentSubscribers(\AcceptanceTester $I) {
     $I->wantTo('View WP user role segment subscribers');
 
     $wp_admin_email = 'test-admin@example.com';
diff --git a/tests/acceptance/WooCommerceCheckoutOptinCest.php b/tests/acceptance/WooCommerceCheckoutOptinCest.php
index 7766a14906..9e7de8181e 100644
--- a/tests/acceptance/WooCommerceCheckoutOptinCest.php
+++ b/tests/acceptance/WooCommerceCheckoutOptinCest.php
@@ -13,7 +13,7 @@ class WooCommerceCheckoutOptinCest {
   /** @var WooCommerceProduct */
   private $product_factory;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->product_factory = new WooCommerceProduct($I);
     $this->settings_factory = new Settings();
@@ -22,7 +22,7 @@ class WooCommerceCheckoutOptinCest {
     $this->settings_factory->withWooCommerceCheckoutOptinEnabled();
   }
 
-  function checkoutWithOptinCheckboxChecked(\AcceptanceTester $I) {
+  public function checkoutWithOptinCheckboxChecked(\AcceptanceTester $I) {
     $customer_email = 'wc_customer_checked@example.com';
     $product = $this->product_factory->create();
     $I->orderProduct($product, $customer_email);
@@ -36,7 +36,7 @@ class WooCommerceCheckoutOptinCest {
     $I->see('WooCommerce Customers', 'td[data-colname="Lists"]');
   }
 
-  function checkoutWithOptinCheckboxUnchecked(\AcceptanceTester $I) {
+  public function checkoutWithOptinCheckboxUnchecked(\AcceptanceTester $I) {
     $customer_email = 'wc_customer_unchecked@example.com';
     $product = $this->product_factory->create();
     $I->orderProduct($product, $customer_email, true, false);
diff --git a/tests/acceptance/WooCommerceCustomerListCest.php b/tests/acceptance/WooCommerceCustomerListCest.php
index 8faee66459..b7035ae6b9 100644
--- a/tests/acceptance/WooCommerceCustomerListCest.php
+++ b/tests/acceptance/WooCommerceCustomerListCest.php
@@ -11,7 +11,7 @@ class WooCommerceCustomerListCest {
   /** @var WooCommerceProduct */
   private $product_factory;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->product_factory = new WooCommerceProduct($I);
     $settings_factory = new Settings();
@@ -20,7 +20,7 @@ class WooCommerceCustomerListCest {
     $settings_factory->withCookieRevenueTrackingDisabled();
   }
 
-  function newCustomerIsAddedToListTest(\AcceptanceTester $I) {
+  public function newCustomerIsAddedToListTest(\AcceptanceTester $I) {
     $customer_email = 'wc_customer@example.com';
     $product = $this->product_factory->create();
     $I->orderProduct($product, $customer_email);
diff --git a/tests/acceptance/WooCommerceEmailCustomizationCest.php b/tests/acceptance/WooCommerceEmailCustomizationCest.php
index d4813108fc..39ea51a882 100644
--- a/tests/acceptance/WooCommerceEmailCustomizationCest.php
+++ b/tests/acceptance/WooCommerceEmailCustomizationCest.php
@@ -15,14 +15,14 @@ class WooCommerceEmailCustomizationCest {
   /** @var string */
   private $wc_customizer_disabled_message;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings = new Settings();
 
     $this->wc_customizer_disabled_message = 'The usage of this email template for your WooCommerce emails is not yet activated.';
   }
 
-  function openEmailCustomizerWhenSettingIsEnabled(\AcceptanceTester $I) {
+  public function openEmailCustomizerWhenSettingIsEnabled(\AcceptanceTester $I) {
     $I->wantTo('Open WooCommerce email customizer while setting is enabled');
 
     $this->createEmailTemplate($I);
@@ -45,7 +45,7 @@ class WooCommerceEmailCustomizationCest {
     $I->dontSee($this->wc_customizer_disabled_message);
   }
 
-  function openEmailCustomizerWhenSettingIsDisabled(\AcceptanceTester $I) {
+  public function openEmailCustomizerWhenSettingIsDisabled(\AcceptanceTester $I) {
     $I->wantTo('Open WooCommerce email customizer while setting is disabled');
 
     $this->createEmailTemplate($I);
diff --git a/tests/acceptance/WooCommerceListImportPageCest.php b/tests/acceptance/WooCommerceListImportPageCest.php
index 9ba015183e..54e4f6cecf 100644
--- a/tests/acceptance/WooCommerceListImportPageCest.php
+++ b/tests/acceptance/WooCommerceListImportPageCest.php
@@ -22,13 +22,13 @@ class WooCommerceListImportPageCest {
     $this->settings = $settings;
   }
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->customer_factory = new WooCommerceCustomer($I);
     $this->order_factory = new WooCommerceOrder($I);
   }
 
-  function importListPageImportTest(\AcceptanceTester $I) {
+  public function importListPageImportTest(\AcceptanceTester $I) {
     $this->settings
       ->withWooCommerceListImportPageDisplayed(false)
       ->withCronTriggerMethod('WordPress');
@@ -65,7 +65,7 @@ class WooCommerceListImportPageCest {
     $I->see($guest_user_data['email']);
   }
 
-  function importPageFormBehaviourTest(\AcceptanceTester $I) {
+  public function importPageFormBehaviourTest(\AcceptanceTester $I) {
     $I->login();
     $I->amOnPage('wp-admin/admin.php?page=mailpoet-woocommerce-list-import');
     $I->see('WooCommerce customers now have their own list');
@@ -89,7 +89,7 @@ class WooCommerceListImportPageCest {
    * can't go to another page unless he submits the form
    * @param \AcceptanceTester $I
    */
-  function importListPageRedirectionTest(\AcceptanceTester $I) {
+  public function importListPageRedirectionTest(\AcceptanceTester $I) {
     $this->settings->withWooCommerceListImportPageDisplayed(false);
     $order = $this->order_factory
       ->withDateCreated('2001-08-22T11:11:56') // any time in the past. Must be before the plugin activation
diff --git a/tests/acceptance/WooCommerceSettingsTabCest.php b/tests/acceptance/WooCommerceSettingsTabCest.php
index 29e41c9102..cd538bfda9 100644
--- a/tests/acceptance/WooCommerceSettingsTabCest.php
+++ b/tests/acceptance/WooCommerceSettingsTabCest.php
@@ -12,14 +12,14 @@ class WooCommerceSettingsTabCest {
   /** @var Settings */
   private $settings_factory;
 
-  function _before(\AcceptanceTester $I) {
+  public function _before(\AcceptanceTester $I) {
     $I->activateWooCommerce();
     $this->settings_factory = new Settings();
     $this->settings_factory->withCookieRevenueTrackingDisabled();
     $this->settings_factory->withWooCommerceListImportPageDisplayed(true);
   }
 
-  function checkWooCommerceTabExists(\AcceptanceTester $I) {
+  public function checkWooCommerceTabExists(\AcceptanceTester $I) {
     $I->wantTo('Check WooCommerce settings tab exists when the WooCommerce plugin is active');
 
     $I->login();
@@ -36,7 +36,7 @@ class WooCommerceSettingsTabCest {
     $I->seeNoJSErrors();
   }
 
-  function checkWooCommercePluginSettingsAreDisabled(\AcceptanceTester $I) {
+  public function checkWooCommercePluginSettingsAreDisabled(\AcceptanceTester $I) {
     $this->settings_factory->withWooCommerceEmailCustomizerEnabled();
 
     $I->wantTo('Check WooCommerce plugin email settings are overlayed with link to MailPoet');
diff --git a/tests/integration/API/APITest.php b/tests/integration/API/APITest.php
index 3982fb9b09..7879da7246 100644
--- a/tests/integration/API/APITest.php
+++ b/tests/integration/API/APITest.php
@@ -6,11 +6,11 @@ use MailPoet\API\API;
 
 class APITest extends \MailPoetTest {
 
-  function testItCallsMPAPI() {
+  public function testItCallsMPAPI() {
     expect(API::MP('v1'))->isInstanceOf('MailPoet\API\MP\v1\API');
   }
 
-  function testItThrowsErrorWhenWrongMPAPIVersionIsCalled() {
+  public function testItThrowsErrorWhenWrongMPAPIVersionIsCalled() {
     try {
       API::MP('invalid_version');
       $this->fail('Incorrect API version exception should have been thrown.');
diff --git a/tests/integration/API/JSON/APITest.php b/tests/integration/API/JSON/APITest.php
index 901e60fc40..ae7d3be0aa 100644
--- a/tests/integration/API/JSON/APITest.php
+++ b/tests/integration/API/JSON/APITest.php
@@ -30,7 +30,7 @@ class APITest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // create WP user
     $this->wp_user_id = null;
@@ -55,7 +55,7 @@ class APITest extends \MailPoetTest {
     );
   }
 
-  function testItCallsAPISetupAction() {
+  public function testItCallsAPISetupAction() {
     $called = false;
     (new WPFunctions)->addAction(
       'mailpoet_api_setup',
@@ -77,7 +77,7 @@ class APITest extends \MailPoetTest {
     expect($called)->true();
   }
 
-  function testItCanAddEndpointNamespaces() {
+  public function testItCanAddEndpointNamespaces() {
     expect($this->api->getEndpointNamespaces())->count(1);
 
     $namespace = [
@@ -91,7 +91,7 @@ class APITest extends \MailPoetTest {
     expect($namespaces[$namespace['version']][0])->equals($namespace['name']);
   }
 
-  function testItReturns400ErrorWhenAPIVersionIsNotSpecified() {
+  public function testItReturns400ErrorWhenAPIVersionIsNotSpecified() {
     $data = [
       'endpoint' => 'a_p_i_test_namespaced_endpoint_stub_v1',
       'method' => 'test',
@@ -101,7 +101,7 @@ class APITest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
   }
 
-  function testItAcceptsAndProcessesAPIVersion() {
+  public function testItAcceptsAndProcessesAPIVersion() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v2',
       'version' => 'v2',
@@ -121,7 +121,7 @@ class APITest extends \MailPoetTest {
     );
   }
 
-  function testItCallsAddedEndpoints() {
+  public function testItCallsAddedEndpoints() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v1',
       'version' => 'v1',
@@ -140,7 +140,7 @@ class APITest extends \MailPoetTest {
     expect($response->getData()['data'])->equals($data['data']);
   }
 
-  function testItCallsAddedEndpointsForSpecificAPIVersion() {
+  public function testItCallsAddedEndpointsForSpecificAPIVersion() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v2',
       'version' => 'v2',
@@ -157,7 +157,7 @@ class APITest extends \MailPoetTest {
     expect($response->getData()['data'])->equals($data['api_version']);
   }
 
-  function testItValidatesPermissionBeforeProcessingEndpointMethod() {
+  public function testItValidatesPermissionBeforeProcessingEndpointMethod() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v1',
       'version' => 'v1',
@@ -193,7 +193,7 @@ class APITest extends \MailPoetTest {
     expect($response->getData()['data'])->equals($data['data']);
   }
 
-  function testItReturnsForbiddenResponseWhenPermissionFailsValidation() {
+  public function testItReturnsForbiddenResponseWhenPermissionFailsValidation() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v1',
       'version' => 'v1',
@@ -216,7 +216,7 @@ class APITest extends \MailPoetTest {
     expect($response->status)->equals(Response::STATUS_FORBIDDEN);
   }
 
-  function testItValidatesGlobalPermission() {
+  public function testItValidatesGlobalPermission() {
     $permissions = [
       'global' => AccessControl::PERMISSION_MANAGE_SETTINGS,
     ];
@@ -247,7 +247,7 @@ class APITest extends \MailPoetTest {
     expect($api->validatePermissions(null, $permissions))->true();
   }
 
-  function testItValidatesEndpointMethodPermission() {
+  public function testItValidatesEndpointMethodPermission() {
     $permissions = [
       'global' => null,
       'methods' => [
@@ -282,7 +282,7 @@ class APITest extends \MailPoetTest {
     expect($api->validatePermissions('test', $permissions))->true();
   }
 
-  function testItThrowsExceptionWhenInvalidEndpointMethodIsCalled() {
+  public function testItThrowsExceptionWhenInvalidEndpointMethodIsCalled() {
     $namespace = [
       'name' => 'MailPoet\API\JSON\v2',
       'version' => 'v2',
@@ -301,7 +301,7 @@ class APITest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Invalid API endpoint method.');
   }
 
-  function _after() {
+  public function _after() {
     wp_delete_user($this->wp_user_id);
   }
 }
diff --git a/tests/integration/API/JSON/APITestNamespacedEndpointStubV1.php b/tests/integration/API/JSON/APITestNamespacedEndpointStubV1.php
index 2d88d5661f..77211c9675 100644
--- a/tests/integration/API/JSON/APITestNamespacedEndpointStubV1.php
+++ b/tests/integration/API/JSON/APITestNamespacedEndpointStubV1.php
@@ -14,11 +14,11 @@ class APITestNamespacedEndpointStubV1 extends APIEndpoint {
     ],
   ];
 
-  function test($data) {
+  public function test($data) {
     return $this->successResponse($data);
   }
 
-  function restricted($data) {
+  public function restricted($data) {
     return $this->successResponse($data);
   }
 }
diff --git a/tests/integration/API/JSON/APITestNamespacedEndpointStubV2.php b/tests/integration/API/JSON/APITestNamespacedEndpointStubV2.php
index dc0d99c914..e98a83af3b 100644
--- a/tests/integration/API/JSON/APITestNamespacedEndpointStubV2.php
+++ b/tests/integration/API/JSON/APITestNamespacedEndpointStubV2.php
@@ -13,7 +13,7 @@ class APITestNamespacedEndpointStubV2 extends APIEndpoint {
     ],
   ];
 
-  function testVersion() {
+  public function testVersion() {
     return $this->successResponse('v2');
   }
 }
diff --git a/tests/integration/API/JSON/v1/AutomatedLatestContentTest.php b/tests/integration/API/JSON/v1/AutomatedLatestContentTest.php
index 62c95cbdec..58ecc812d1 100644
--- a/tests/integration/API/JSON/v1/AutomatedLatestContentTest.php
+++ b/tests/integration/API/JSON/v1/AutomatedLatestContentTest.php
@@ -6,7 +6,7 @@ use MailPoet\API\JSON\v1\AutomatedLatestContent;
 use MailPoet\WP\Functions as WPFunctions;
 
 class AutomatedLatestContentTest extends \MailPoetTest {
-  function testItGetsPostTypes() {
+  public function testItGetsPostTypes() {
     $endpoint = new AutomatedLatestContent(new \MailPoet\Newsletter\AutomatedLatestContent(), new WPFunctions);
     $response = $endpoint->getPostTypes();
     expect($response->data)->notEmpty();
@@ -17,7 +17,7 @@ class AutomatedLatestContentTest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotGetPostTypesExludedFromSearch() {
+  public function testItDoesNotGetPostTypesExludedFromSearch() {
     $endpoint = new AutomatedLatestContent(new \MailPoet\Newsletter\AutomatedLatestContent(), new WPFunctions);
     $response = $endpoint ->getPostTypes();
     // WP's default post type 'revision' is excluded from search
diff --git a/tests/integration/API/JSON/v1/AutomaticEmailsTest.php b/tests/integration/API/JSON/v1/AutomaticEmailsTest.php
index 6271a638c3..581a8b0d14 100644
--- a/tests/integration/API/JSON/v1/AutomaticEmailsTest.php
+++ b/tests/integration/API/JSON/v1/AutomaticEmailsTest.php
@@ -5,10 +5,10 @@ namespace MailPoet\API\JSON\v1;
 use MailPoet\WP\Functions as WPFunctions;
 
 class AutomaticEmailsTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     $this->wp = new WPFunctions;
   }
-  function testItRequiresProperlyFormattedRequestWhenGettingEventOptions() {
+  public function testItRequiresProperlyFormattedRequestWhenGettingEventOptions() {
     $API = new AutomaticEmails();
     $expected_error_message = 'Improperly formatted request.';
 
@@ -53,7 +53,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($result->errors[0]['message'])->equals($expected_error_message);
   }
 
-  function testItRequiresValidEventFilterWhenGettingEventOptions() {
+  public function testItRequiresValidEventFilterWhenGettingEventOptions() {
     $API = new AutomaticEmails();
     $expected_error_message = 'Automatic email event filter does not exist.';
 
@@ -94,7 +94,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('test_filter');
   }
 
-  function testItGetsEventOptions() {
+  public function testItGetsEventOptions() {
     $API = new AutomaticEmails();
 
     $this->wp->addFilter('mailpoet_automatic_email_test', function() {
@@ -133,7 +133,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('test_filter');
   }
 
-  function testItRequiresProperlyFormattedRequestWhenGettingEventShortcodes() {
+  public function testItRequiresProperlyFormattedRequestWhenGettingEventShortcodes() {
     $API = new AutomaticEmails();
     $expected_error_message = 'Improperly formatted request.';
 
@@ -154,7 +154,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($result->errors[0]['message'])->equals($expected_error_message);
   }
 
-  function testItRequiresValidEventWhenGettingEventShortcodes() {
+  public function testItRequiresValidEventWhenGettingEventShortcodes() {
     $API = new AutomaticEmails();
     $expected_error_message = 'Automatic email event does not exist.';
 
@@ -185,7 +185,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
 
-  function testItGetsEventShortcodes() {
+  public function testItGetsEventShortcodes() {
     $API = new AutomaticEmails();
     $shortcodes = [
       [
diff --git a/tests/integration/API/JSON/v1/CustomFieldsTest.php b/tests/integration/API/JSON/v1/CustomFieldsTest.php
index b136bdfa39..129baafaff 100644
--- a/tests/integration/API/JSON/v1/CustomFieldsTest.php
+++ b/tests/integration/API/JSON/v1/CustomFieldsTest.php
@@ -59,7 +59,7 @@ class CustomFieldsTest extends \MailPoetTest {
     ],
   ];
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->repository = ContainerWrapper::getInstance(WP_DEBUG)->get(CustomFieldsRepository::class);
     $this->repository->truncate();
@@ -68,7 +68,7 @@ class CustomFieldsTest extends \MailPoetTest {
     }
   }
 
-  function testItCanGetAllCustomFields() {
+  public function testItCanGetAllCustomFields() {
     $router = new CustomFields($this->repository, new CustomFieldsResponseBuilder());
     $response = $router->getAll();
     expect($response->status)->equals(APIResponse::STATUS_OK);
@@ -81,7 +81,7 @@ class CustomFieldsTest extends \MailPoetTest {
     }
   }
 
-  function testItCanDeleteACustomField() {
+  public function testItCanDeleteACustomField() {
     $custom_field = CustomField::where('type', 'date')->findOne();
     $custom_field_id = $custom_field->id();
 
@@ -96,7 +96,7 @@ class CustomFieldsTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
   }
 
-  function testItCanSaveACustomField() {
+  public function testItCanSaveACustomField() {
     $new_custom_field = [
       'name' => 'New custom field',
       'type' => 'text',
@@ -120,7 +120,7 @@ class CustomFieldsTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
   }
 
-  function testItCanGetACustomField() {
+  public function testItCanGetACustomField() {
     $custom_field = $this->repository->findOneBy(['name' => 'CF: text']);
 
     $router = new CustomFields($this->repository, new CustomFieldsResponseBuilder());
diff --git a/tests/integration/API/JSON/v1/DynamicSegmentsTest.php b/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
index 433019ba1c..1fff6a1273 100644
--- a/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
+++ b/tests/integration/API/JSON/v1/DynamicSegmentsTest.php
@@ -27,12 +27,12 @@ class DynamicSegmentsTest extends \MailPoetTest {
   /** @var Handler */
   private $listing_handler;
 
-  function _before() {
+  public function _before() {
     $this->bulk_action = ContainerWrapper::getInstance()->get(BulkActionController::class);
     $this->listing_handler = ContainerWrapper::getInstance()->get(Handler::class);
   }
 
-  function testGetReturnsResponse() {
+  public function testGetReturnsResponse() {
     $loader = Stub::makeEmpty('\MailPoet\DynamicSegments\Persistence\Loading\SingleSegmentLoader', [
       'load' => function () {
         $dynamic_segment = DynamicSegment::create();
@@ -58,7 +58,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     ]);
   }
 
-  function testGetReturnsError() {
+  public function testGetReturnsError() {
     $loader = Stub::makeEmpty('\MailPoet\DynamicSegments\Persistence\Loading\SingleSegmentLoader', [
       'load' => function () {
         throw new \InvalidArgumentException('segment not found');
@@ -70,7 +70,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     expect($response->status)->equals(self::SEGMENT_NOT_FOUND_RESPONSE_CODE);
   }
 
-  function testSaverSavesData() {
+  public function testSaverSavesData() {
     $mapper = Stub::makeEmpty('\MailPoet\DynamicSegments\Mappers\FormDataMapper', ['mapDataToDB' => Expected::once(function () {
       $dynamic_segment = DynamicSegment::create();
       $dynamic_segment->hydrate([
@@ -87,7 +87,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     expect($response->status)->equals(self::SUCCESS_RESPONSE_CODE);
   }
 
-  function testSaverReturnsErrorOnInvalidData() {
+  public function testSaverReturnsErrorOnInvalidData() {
     $mapper = Stub::makeEmpty('\MailPoet\DynamicSegments\Mappers\FormDataMapper', ['mapDataToDB' => Expected::once(function () {
       throw new InvalidSegmentTypeException();
     })]);
@@ -99,7 +99,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     expect($response->status)->equals(self::INVALID_DATA_RESPONSE_CODE);
   }
 
-  function testSaverReturnsErrorOnSave() {
+  public function testSaverReturnsErrorOnSave() {
     $mapper = Stub::makeEmpty('\MailPoet\DynamicSegments\Mappers\FormDataMapper', ['mapDataToDB' => Expected::once(function () {
       $dynamic_segment = DynamicSegment::create();
       $dynamic_segment->hydrate([
@@ -119,7 +119,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Error saving data');
   }
 
-  function testItCanTrashASegment() {
+  public function testItCanTrashASegment() {
     DynamicSegment::deleteMany();
     $dynamic_segment = DynamicSegment::createOrUpdate([
       'name' => 'Trash test',
@@ -144,7 +144,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     $dynamic_segment->delete();
   }
 
-  function testItCanRestoreASegment() {
+  public function testItCanRestoreASegment() {
     DynamicSegment::deleteMany();
     $dynamic_segment = DynamicSegment::createOrUpdate([
       'name' => 'Restore test',
@@ -169,7 +169,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     $dynamic_segment->delete();
   }
 
-  function testItCanDeleteASegment() {
+  public function testItCanDeleteASegment() {
     DynamicSegment::deleteMany();
     $dynamic_segment = DynamicSegment::createOrUpdate([
       'name' => 'Delete test',
@@ -195,7 +195,7 @@ class DynamicSegmentsTest extends \MailPoetTest {
     expect(DynamicSegmentFilter::findOne($filter->id))->equals(false);
   }
 
-  function testItCanBulkDeleteSegments() {
+  public function testItCanBulkDeleteSegments() {
     DynamicSegment::deleteMany();
     $dynamic_segment_1 = DynamicSegment::createOrUpdate([
       'name' => 'Test 1',
diff --git a/tests/integration/API/JSON/v1/FeatureFlagsTest.php b/tests/integration/API/JSON/v1/FeatureFlagsTest.php
index ee1eb11ecc..4668640373 100644
--- a/tests/integration/API/JSON/v1/FeatureFlagsTest.php
+++ b/tests/integration/API/JSON/v1/FeatureFlagsTest.php
@@ -17,14 +17,14 @@ class FeatureFlagsTest extends \MailPoetTest {
   /** @var FeatureFlagsRepository */
   private $repository;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->repository = $this->di_container->get(FeatureFlagsRepository::class);
     $table_name = $this->entity_manager->getClassMetadata(FeatureFlagEntity::class)->getTableName();
     $this->entity_manager->getConnection()->executeUpdate("TRUNCATE $table_name");
   }
 
-  function testItReturnsDefaults() {
+  public function testItReturnsDefaults() {
     $endpoint = $this->createEndpointWithFeatureDefaults([
       'feature-a' => true,
       'feature-b' => false,
@@ -44,7 +44,7 @@ class FeatureFlagsTest extends \MailPoetTest {
     ]);
   }
 
-  function testItReturnsDatabaseValue() {
+  public function testItReturnsDatabaseValue() {
     $this->repository->createOrUpdate([
       'name' => 'feature-a',
       'value' => false,
@@ -63,7 +63,7 @@ class FeatureFlagsTest extends \MailPoetTest {
     ]);
   }
 
-  function testItSetsDatabaseValue() {
+  public function testItSetsDatabaseValue() {
     $endpoint = $this->createEndpointWithFeatureDefaults([
       'feature-a' => true,
     ]);
@@ -80,7 +80,7 @@ class FeatureFlagsTest extends \MailPoetTest {
   }
 
 
-  function testItUpdatesDatabaseValue() {
+  public function testItUpdatesDatabaseValue() {
     $this->repository->createOrUpdate([
       'name' => 'feature-a',
       'value' => false,
@@ -101,7 +101,7 @@ class FeatureFlagsTest extends \MailPoetTest {
     expect($features[0]->getValue())->equals(true);
   }
 
-  function testItDoesNotReturnUnknownFlag() {
+  public function testItDoesNotReturnUnknownFlag() {
     $this->repository->createOrUpdate([
       'name' => 'feature-unknown',
       'value' => true,
@@ -111,7 +111,7 @@ class FeatureFlagsTest extends \MailPoetTest {
     expect($endpoint->getAll()->data)->isEmpty();
   }
 
-  function testItDoesNotSaveUnknownFlag() {
+  public function testItDoesNotSaveUnknownFlag() {
     $endpoint = $this->createEndpointWithFeatureDefaults([]);
     $response = $endpoint->set([
       'feature-unknown' => false,
diff --git a/tests/integration/API/JSON/v1/FormsTest.php b/tests/integration/API/JSON/v1/FormsTest.php
index 9fb529b997..9567dafda2 100644
--- a/tests/integration/API/JSON/v1/FormsTest.php
+++ b/tests/integration/API/JSON/v1/FormsTest.php
@@ -13,7 +13,7 @@ class FormsTest extends \MailPoetTest {
   /** @var Forms */
   private $endpoint;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->endpoint = ContainerWrapper::getInstance()->get(Forms::class);
     $this->form_1 = Form::createOrUpdate(['name' => 'Form 1']);
@@ -23,7 +23,7 @@ class FormsTest extends \MailPoetTest {
     Segment::createOrUpdate(['name' => 'Segment 2']);
   }
 
-  function testItCanGetAForm() {
+  public function testItCanGetAForm() {
     $response = $this->endpoint->get(/* missing id */);
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
     expect($response->errors[0]['message'])->equals('This form does not exist.');
@@ -39,7 +39,7 @@ class FormsTest extends \MailPoetTest {
     );
   }
 
-  function testItCanGetListingData() {
+  public function testItCanGetListingData() {
     $response = $this->endpoint->listing();
 
     expect($response->status)->equals(APIResponse::STATUS_OK);
@@ -54,7 +54,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->data[2]['name'])->equals('Form 3');
   }
 
-  function testItCanCreateANewForm() {
+  public function testItCanCreateANewForm() {
     $response = $this->endpoint->create();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -63,7 +63,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->data['name'])->equals('New form');
   }
 
-  function testItCanSaveAForm() {
+  public function testItCanSaveAForm() {
     $form_data = [
       'name' => 'My first form',
     ];
@@ -75,7 +75,7 @@ class FormsTest extends \MailPoetTest {
     );
   }
 
-  function testItCanPreviewAForm() {
+  public function testItCanPreviewAForm() {
     $response = $this->endpoint->create();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -88,7 +88,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->data['css'])->notEmpty();
   }
 
-  function testItCanExportAForm() {
+  public function testItCanExportAForm() {
     $response = $this->endpoint->create();
     expect($response->status)->equals(APIResponse::STATUS_OK);
 
@@ -99,7 +99,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->data['shortcode'])->notEmpty();
   }
 
-  function testItCanSaveFormEditor() {
+  public function testItCanSaveFormEditor() {
     $response = $this->endpoint->create();
     expect($response->status)->equals(APIResponse::STATUS_OK);
 
@@ -112,7 +112,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->data['name'])->equals('Updated form');
   }
 
-  function testItCanRestoreAForm() {
+  public function testItCanRestoreAForm() {
     $this->form_1->trash();
 
     $trashed_form = Form::findOne($this->form_1->id);
@@ -127,7 +127,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanTrashAForm() {
+  public function testItCanTrashAForm() {
     $response = $this->endpoint->trash(['id' => $this->form_2->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -137,14 +137,14 @@ class FormsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDeleteAForm() {
+  public function testItCanDeleteAForm() {
     $response = $this->endpoint->delete(['id' => $this->form_3->id]);
     expect($response->data)->isEmpty();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDuplicateAForm() {
+  public function testItCanDuplicateAForm() {
     $response = $this->endpoint->duplicate(['id' => $this->form_1->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -153,7 +153,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanBulkDeleteForms() {
+  public function testItCanBulkDeleteForms() {
     $response = $this->endpoint->bulkAction([
       'action' => 'trash',
       'listing' => ['group' => 'all'],
@@ -176,7 +176,7 @@ class FormsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(0);
   }
 
-  function _after() {
+  public function _after() {
     Form::deleteMany();
     Segment::deleteMany();
   }
diff --git a/tests/integration/API/JSON/v1/ImportExportTest.php b/tests/integration/API/JSON/v1/ImportExportTest.php
index 2b2b1bb97e..0ff4cc6dc0 100644
--- a/tests/integration/API/JSON/v1/ImportExportTest.php
+++ b/tests/integration/API/JSON/v1/ImportExportTest.php
@@ -13,13 +13,13 @@ class ImportExportTest extends \MailPoetTest {
   /** @var ImportExport */
   private $endpoint;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->endpoint = ContainerWrapper::getInstance()->get(ImportExport::class);
     ScheduledTask::where('type', WooCommerceSync::TASK_TYPE)->deleteMany();
   }
 
-  function testItSchedulesTaskWhenNoneExistss() {
+  public function testItSchedulesTaskWhenNoneExistss() {
     $response = $this->endpoint->setupWooCommerceInitialImport();
     expect($response->status)->equals(200);
     $task = ScheduledTask::where('type', WooCommerceSync::TASK_TYPE)->findOne();
@@ -30,7 +30,7 @@ class ImportExportTest extends \MailPoetTest {
     expect($scheduled_at->timestamp)->lessOrEquals($now + 1);
   }
 
-  function testItReschedulesScheduledTaskToNow() {
+  public function testItReschedulesScheduledTaskToNow() {
     $original_schedule = Carbon::createFromTimestamp(time() + 3000);
     $this->createTask(WooCommerceSync::TASK_TYPE, ScheduledTask::STATUS_SCHEDULED, $original_schedule);
     $this->endpoint->setupWooCommerceInitialImport();
@@ -44,7 +44,7 @@ class ImportExportTest extends \MailPoetTest {
     expect($task_count)->equals(1);
   }
 
-  function testItDoesNothingForRunningTask() {
+  public function testItDoesNothingForRunningTask() {
     $this->createTask(WooCommerceSync::TASK_TYPE, null);
     $this->endpoint->setupWooCommerceInitialImport();
     $task = ScheduledTask::where('type', WooCommerceSync::TASK_TYPE)->findOne();
@@ -53,7 +53,7 @@ class ImportExportTest extends \MailPoetTest {
     expect($task_count)->equals(1);
   }
 
-  function testItIgnoresCompletedAndPausedTasks() {
+  public function testItIgnoresCompletedAndPausedTasks() {
     $this->createTask(WooCommerceSync::TASK_TYPE, ScheduledTask::STATUS_PAUSED);
     $this->createTask(WooCommerceSync::TASK_TYPE, ScheduledTask::STATUS_COMPLETED);
     $this->endpoint->setupWooCommerceInitialImport();
diff --git a/tests/integration/API/JSON/v1/MailerTest.php b/tests/integration/API/JSON/v1/MailerTest.php
index 52b2196d40..9491050405 100644
--- a/tests/integration/API/JSON/v1/MailerTest.php
+++ b/tests/integration/API/JSON/v1/MailerTest.php
@@ -12,7 +12,7 @@ use MailPoet\Services\Bridge;
 use MailPoet\Settings\SettingsController;
 
 class MailerTest extends \MailPoetTest {
-  function testItResumesSending() {
+  public function testItResumesSending() {
     // create mailer log with a "paused" status
     $mailer_log = ['status' => MailerLog::STATUS_PAUSED];
     MailerLog::updateMailerLog($mailer_log);
@@ -29,7 +29,7 @@ class MailerTest extends \MailPoetTest {
     expect($mailer_log['status'])->null();
   }
 
-  function testItRunsAuhtorizedEmailsCheckIfErrorIsPresent() {
+  public function testItRunsAuhtorizedEmailsCheckIfErrorIsPresent() {
     $settings = SettingsController::getInstance();
     $settings->set(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING, ['invalid_sender_address' => 'a@b.c']);
     $authorized_emails_controller = $this->makeEmpty(AuthorizedEmailsController::class, ['checkAuthorizedEmailAddresses' => Expected::once()]);
diff --git a/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php b/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
index 0513189eb9..3a7b2b31db 100644
--- a/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
+++ b/tests/integration/API/JSON/v1/NewsletterTemplatesTest.php
@@ -7,7 +7,7 @@ use MailPoet\API\JSON\v1\NewsletterTemplates;
 use MailPoet\Models\NewsletterTemplate;
 
 class NewsletterTemplatesTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     NewsletterTemplate::deleteMany();
     NewsletterTemplate::createOrUpdate([
@@ -22,7 +22,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanGetANewsletterTemplate() {
+  public function testItCanGetANewsletterTemplate() {
     $template = NewsletterTemplate::where('name', 'Template #1')->findOne();
 
     $router = new NewsletterTemplates();
@@ -43,7 +43,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     );
   }
 
-  function testItCanGetAllNewsletterTemplates() {
+  public function testItCanGetAllNewsletterTemplates() {
     $templates = NewsletterTemplate::count();
 
     $router = new NewsletterTemplates();
@@ -52,7 +52,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     expect($response->data)->count($templates);
   }
 
-  function testItCanSaveANewTemplate() {
+  public function testItCanSaveANewTemplate() {
     $template_data = [
       'name' => 'Template #3',
       'body' => '{"key3": "value3"}',
@@ -66,7 +66,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     );
   }
 
-  function testItCanSaveANewTemplateAssociatedWithANewsletter() {
+  public function testItCanSaveANewTemplateAssociatedWithANewsletter() {
     $template_data = [
       'newsletter_id' => 2,
       'name' => 'Template #3',
@@ -81,7 +81,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     );
   }
 
-  function testItCanUpdateTemplateAssociatedWithANewsletter() {
+  public function testItCanUpdateTemplateAssociatedWithANewsletter() {
     $template_data = [
       'newsletter_id' => '1',
       'name' => 'Template #2',
@@ -111,7 +111,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     expect($normalize($template))->equals($template_data);
   }
 
-  function testItCanDeleteANewsletterTemplate() {
+  public function testItCanDeleteANewsletterTemplate() {
     $template = NewsletterTemplate::where('name', 'Template #2')->findOne();
     expect($template->deleted_at)->null();
 
@@ -128,7 +128,7 @@ class NewsletterTemplatesTest extends \MailPoetTest {
     expect($deleted_template)->false();
   }
 
-  function _after() {
+  public function _after() {
     NewsletterTemplate::deleteMany();
   }
 }
diff --git a/tests/integration/API/JSON/v1/NewslettersTest.php b/tests/integration/API/JSON/v1/NewslettersTest.php
index fe84b2c63e..00492c6e20 100644
--- a/tests/integration/API/JSON/v1/NewslettersTest.php
+++ b/tests/integration/API/JSON/v1/NewslettersTest.php
@@ -50,7 +50,7 @@ class NewslettersTest extends \MailPoetTest {
   /** @var CronHelper */
   private $cron_helper;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->subscription_url_factory = SubscriptionUrlFactory::getInstance();
     $this->cron_helper = ContainerWrapper::getInstance()->get(CronHelper::class);
@@ -81,7 +81,7 @@ class NewslettersTest extends \MailPoetTest {
       ]);
   }
 
-  function testItKeepsUnsentNewslettersAtTheTopWhenSortingBySentAtDate() {
+  public function testItKeepsUnsentNewslettersAtTheTopWhenSortingBySentAtDate() {
     $sent_newsletters = [];
     for ($i = 1; $i <= 3; $i++) {
       $sent_newsletters[$i] = Newsletter::create();
@@ -124,7 +124,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->data[3]['id'])->equals($sent_newsletters[1]->id);
   }
 
-  function testItCanGetANewsletter() {
+  public function testItCanGetANewsletter() {
     $response = $this->endpoint->get(); // missing id
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
     expect($response->errors[0]['message'])
@@ -168,7 +168,7 @@ class NewslettersTest extends \MailPoetTest {
     expect(WPHooksHelper::getFilterApplied($hook_name)[0])->internalType('array');
   }
 
-  function testItCanSaveANewNewsletter() {
+  public function testItCanSaveANewNewsletter() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'some_option';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_STANDARD;
@@ -237,7 +237,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please specify a type.');
   }
 
-  function testItCanSaveAnExistingNewsletter() {
+  public function testItCanSaveAnExistingNewsletter() {
     $newsletter_data = [
       'id' => $this->newsletter->id,
       'subject' => 'My Updated Newsletter',
@@ -250,7 +250,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($updated_newsletter->subject)->equals('My Updated Newsletter');
   }
 
-  function testItDoesNotRerenderPostNotificationsUponUpdate() {
+  public function testItDoesNotRerenderPostNotificationsUponUpdate() {
     $sending_queue = SendingTask::create();
     $sending_queue->newsletter_id = $this->post_notification->id;
     $sending_queue->status = SendingQueue::STATUS_SCHEDULED;
@@ -275,7 +275,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($updated_queue['newsletter_rendered_subject'])->null();
   }
 
-  function testItCanRerenderQueueUponSave() {
+  public function testItCanRerenderQueueUponSave() {
     $sending_queue = SendingTask::create();
     $sending_queue->newsletter_id = $this->newsletter->id;
     $sending_queue->status = SendingQueue::STATUS_SCHEDULED;
@@ -301,7 +301,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($updated_queue['newsletter_rendered_subject'])->equals('My Updated Newsletter');
   }
 
-  function testItCanUpdatePostNotificationScheduleUponSave() {
+  public function testItCanUpdatePostNotificationScheduleUponSave() {
     $newsletter_options = [
       'intervalType',
       'timeOfDay',
@@ -345,7 +345,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($saved_newsletter->schedule)->equals('* * * * *');
   }
 
-  function testItCanReschedulePreviouslyScheduledSendingQueueJobs() {
+  public function testItCanReschedulePreviouslyScheduledSendingQueueJobs() {
     // create newsletter options
     $newsletter_options = [
       'intervalType',
@@ -399,7 +399,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($sending_queue_2->scheduled_at)->null();
   }
 
-  function testItCanModifySegmentsOfExistingNewsletter() {
+  public function testItCanModifySegmentsOfExistingNewsletter() {
     $segment_1 = Segment::createOrUpdate(['name' => 'Segment 1']);
     $fake_segment_id = 1;
 
@@ -423,7 +423,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($updated_newsletter->segments[0]['name'])->equals('Segment 1');
   }
 
-  function testItReturnsErrorIfSubscribersLimitReached() {
+  public function testItReturnsErrorIfSubscribersLimitReached() {
     $endpoint = new Newsletters(
       ContainerWrapper::getInstance()->get(BulkActionController::class),
       ContainerWrapper::getInstance()->get(Handler::class),
@@ -447,7 +447,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($res->status)->equals(APIResponse::STATUS_FORBIDDEN);
   }
 
-  function testItCanSetANewsletterStatus() {
+  public function testItCanSetANewsletterStatus() {
     // set status to sending
     $response = $this->endpoint->setStatus
     ([
@@ -489,7 +489,7 @@ class NewslettersTest extends \MailPoetTest {
       ->equals('This email does not exist.');
   }
 
-  function testItReschedulesPastDuePostNotificationsWhenStatusIsSetBackToActive() {
+  public function testItReschedulesPastDuePostNotificationsWhenStatusIsSetBackToActive() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -533,7 +533,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($tasks[2]->scheduled_at)->equals(Scheduler::getPreviousRunDate($schedule));
   }
 
-  function testItSchedulesPostNotificationsWhenStatusIsSetBackToActive() {
+  public function testItSchedulesPostNotificationsWhenStatusIsSetBackToActive() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -557,7 +557,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($tasks)->notEmpty();
   }
 
-  function testItCanRestoreANewsletter() {
+  public function testItCanRestoreANewsletter() {
     $this->newsletter->trash();
 
     $trashed_newsletter = Newsletter::findOne($this->newsletter->id);
@@ -573,7 +573,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanTrashANewsletter() {
+  public function testItCanTrashANewsletter() {
     $response = $this->endpoint->trash(['id' => $this->newsletter->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -584,14 +584,14 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDeleteANewsletter() {
+  public function testItCanDeleteANewsletter() {
     $response = $this->endpoint->delete(['id' => $this->newsletter->id]);
     expect($response->data)->isEmpty();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDuplicateANewsletter() {
+  public function testItCanDuplicateANewsletter() {
     $wp = Stub::make(new WPFunctions, [
       'doAction' => asCallable([WPHooksHelper::class, 'doAction']),
     ]);
@@ -635,7 +635,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanCreateANewsletter() {
+  public function testItCanCreateANewsletter() {
     $data = [
       'subject' => 'My New Newsletter',
       'type' => Newsletter::TYPE_STANDARD,
@@ -653,7 +653,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please specify a type.');
   }
 
-  function testItCanGetListingData() {
+  public function testItCanGetListingData() {
     $segment_1 = Segment::createOrUpdate(['name' => 'Segment 1']);
     $segment_2 = Segment::createOrUpdate(['name' => 'Segment 2']);
 
@@ -709,7 +709,7 @@ class NewslettersTest extends \MailPoetTest {
       ->equals($segment_2->id);
   }
 
-  function testItCanFilterListing() {
+  public function testItCanFilterListing() {
     // create 2 segments
     $segment_1 = Segment::createOrUpdate(['name' => 'Segment 1']);
     $segment_2 = Segment::createOrUpdate(['name' => 'Segment 2']);
@@ -773,7 +773,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(2);
   }
 
-  function testItCanLimitListing() {
+  public function testItCanLimitListing() {
     // get 1st page (limit items per page to 1)
     $response = $this->endpoint->listing(
       [
@@ -808,7 +808,7 @@ class NewslettersTest extends \MailPoetTest {
     );
   }
 
-  function testItCanBulkDeleteSelectionOfNewsletters() {
+  public function testItCanBulkDeleteSelectionOfNewsletters() {
     $selection_ids = [
       $this->newsletter->id,
       $this->post_notification->id,
@@ -827,7 +827,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(count($selection_ids));
   }
 
-  function testItCanBulkDeleteNewsletters() {
+  public function testItCanBulkDeleteNewsletters() {
     $response = $this->endpoint->bulkAction(
       [
         'action' => 'trash',
@@ -856,7 +856,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(0);
   }
 
-  function testItCanSendAPreview() {
+  public function testItCanSendAPreview() {
 
     $subscriber = 'test@subscriber.com';
 
@@ -894,7 +894,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_OK);
   }
 
-  function testItReturnsMailerErrorWhenSendingFailed() {
+  public function testItReturnsMailerErrorWhenSendingFailed() {
     $subscriber = 'test@subscriber.com';
 
     $endpoint = Stub::copy($this->endpoint, [
@@ -927,7 +927,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('The email could not be sent: failed');
   }
 
-  function testItReturnsBrowserPreviewUrlWithoutProtocol() {
+  public function testItReturnsBrowserPreviewUrlWithoutProtocol() {
     $data = [
       'id' => $this->newsletter->id,
       'body' => 'fake body',
@@ -967,7 +967,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($response->meta['preview_url'])->regExp('!^\/\/!');
   }
 
-  function testItGeneratesPreviewLinksWithNewsletterHashAndNoSubscriberData() {
+  public function testItGeneratesPreviewLinksWithNewsletterHashAndNoSubscriberData() {
     $response = $this->endpoint->listing();
     $preview_link = $response->data[0]['preview_url'];
     parse_str(parse_url($preview_link, PHP_URL_QUERY), $preview_link_data);
@@ -978,7 +978,7 @@ class NewslettersTest extends \MailPoetTest {
     expect((boolean)$preview_link_data['preview'])->true();
   }
 
-  function testItDeletesSendingQueueAndSetsNewsletterStatusToDraftWhenItIsUnscheduled() {
+  public function testItDeletesSendingQueueAndSetsNewsletterStatusToDraftWhenItIsUnscheduled() {
     $newsletter = $this->newsletter;
     $newsletter->status = Newsletter::STATUS_SCHEDULED;
     $newsletter->save();
@@ -1009,7 +1009,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($sending_queue)->false();
   }
 
-  function testItSavesDefaultSenderIfNeeded() {
+  public function testItSavesDefaultSenderIfNeeded() {
     $settings = $this->di_container->get(SettingsController::class);
     $settings->set('sender', null);
 
@@ -1025,7 +1025,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($settings->get('sender.address'))->same('test@example.com');
   }
 
-  function testItDoesntSaveDefaultSenderWhenEmptyValues() {
+  public function testItDoesntSaveDefaultSenderWhenEmptyValues() {
     $settings = $this->di_container->get(SettingsController::class);
     $settings->set('sender', null);
 
@@ -1040,7 +1040,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($settings->get('sender'))->null();
   }
 
-  function testItDoesntOverrideDefaultSender() {
+  public function testItDoesntOverrideDefaultSender() {
     $settings = $this->di_container->get(SettingsController::class);
     $settings->set('sender', [
       'name' => 'Test sender',
@@ -1059,7 +1059,7 @@ class NewslettersTest extends \MailPoetTest {
     expect($settings->get('sender.address'))->same('test@example.com');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
diff --git a/tests/integration/API/JSON/v1/SegmentsTest.php b/tests/integration/API/JSON/v1/SegmentsTest.php
index 876f9437d7..709036e367 100644
--- a/tests/integration/API/JSON/v1/SegmentsTest.php
+++ b/tests/integration/API/JSON/v1/SegmentsTest.php
@@ -14,7 +14,7 @@ class SegmentsTest extends \MailPoetTest {
   /** @var Segments */
   private $endpoint;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->endpoint = ContainerWrapper::getInstance()->get(Segments::class);
     $this->segment_1 = Segment::createOrUpdate(['name' => 'Segment 1', 'type' => 'default']);
@@ -22,7 +22,7 @@ class SegmentsTest extends \MailPoetTest {
     $this->segment_3 = Segment::createOrUpdate(['name' => 'Segment 3', 'type' => 'default']);
   }
 
-  function testItCanGetASegment() {
+  public function testItCanGetASegment() {
     $response = $this->endpoint->get(/* missing id */);
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
     expect($response->errors[0]['message'])->equals('This list does not exist.');
@@ -38,7 +38,7 @@ class SegmentsTest extends \MailPoetTest {
     );
   }
 
-  function testItCanGetListingData() {
+  public function testItCanGetListingData() {
     $response = $this->endpoint->listing();
 
     expect($response->status)->equals(APIResponse::STATUS_OK);
@@ -53,7 +53,7 @@ class SegmentsTest extends \MailPoetTest {
     expect($response->data[2]['name'])->equals($this->segment_3->name);
   }
 
-  function testItCanSaveASegment() {
+  public function testItCanSaveASegment() {
     $segment_data = [
       'name' => 'New Segment',
     ];
@@ -69,7 +69,7 @@ class SegmentsTest extends \MailPoetTest {
     );
   }
 
-  function testItCannotSaveDuplicate() {
+  public function testItCannotSaveDuplicate() {
     $duplicate_entry = [
       'name' => 'Segment 1',
     ];
@@ -81,7 +81,7 @@ class SegmentsTest extends \MailPoetTest {
     );
   }
 
-  function testItCanRestoreASegment() {
+  public function testItCanRestoreASegment() {
     $this->segment_1->trash();
 
     $trashed_segment = Segment::findOne($this->segment_1->id);
@@ -96,7 +96,7 @@ class SegmentsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanTrashASegment() {
+  public function testItCanTrashASegment() {
     $response = $this->endpoint->trash(['id' => $this->segment_2->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -106,14 +106,14 @@ class SegmentsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDeleteASegment() {
+  public function testItCanDeleteASegment() {
     $response = $this->endpoint->delete(['id' => $this->segment_3->id]);
     expect($response->data)->isEmpty();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDuplicateASegment() {
+  public function testItCanDuplicateASegment() {
     $response = $this->endpoint->duplicate(['id' => $this->segment_1->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -122,7 +122,7 @@ class SegmentsTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanBulkDeleteSegments() {
+  public function testItCanBulkDeleteSegments() {
     $subscriber_segment = SubscriberSegment::createOrUpdate([
       'subscriber_id' => 1,
       'segment_id' => $this->segment_1->id,
@@ -154,7 +154,7 @@ class SegmentsTest extends \MailPoetTest {
     expect(SubscriberSegment::findOne($subscriber_segment->id))->equals(false);
   }
 
-  function _after() {
+  public function _after() {
     Segment::deleteMany();
   }
 }
diff --git a/tests/integration/API/JSON/v1/SendingQueueTest.php b/tests/integration/API/JSON/v1/SendingQueueTest.php
index 9da331c4af..928baa7708 100644
--- a/tests/integration/API/JSON/v1/SendingQueueTest.php
+++ b/tests/integration/API/JSON/v1/SendingQueueTest.php
@@ -20,7 +20,7 @@ use MailPoet\Util\License\Features\Subscribers as SubscribersFeature;
 use MailPoetVendor\Idiorm\ORM;
 
 class SendingQueueTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter = Newsletter::createOrUpdate(
       [
@@ -36,7 +36,7 @@ class SendingQueueTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCreatesNewScheduledSendingQueueTask() {
+  public function testItCreatesNewScheduledSendingQueueTask() {
     $newsletter = $this->newsletter;
     $newsletter->status = Newsletter::STATUS_SCHEDULED;
     $newsletter->save();
@@ -58,7 +58,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($scheduled_task->type)->equals(Sending::TASK_TYPE);
   }
 
-  function testItReturnsErrorIfSubscribersLimitReached() {
+  public function testItReturnsErrorIfSubscribersLimitReached() {
     $sending_queue = new SendingQueueAPI(Stub::make(SubscribersFeature::class, [
       'check' => true,
     ]));
@@ -68,7 +68,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($res->status)->equals(APIResponse::STATUS_FORBIDDEN);
   }
 
-  function testItReschedulesScheduledSendingQueueTask() {
+  public function testItReschedulesScheduledSendingQueueTask() {
     $newsletter = $this->newsletter;
     $newsletter->status = Newsletter::STATUS_SCHEDULED;
     $newsletter->save();
@@ -130,7 +130,7 @@ class SendingQueueTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
diff --git a/tests/integration/API/JSON/v1/SendingTaskSubscribersTest.php b/tests/integration/API/JSON/v1/SendingTaskSubscribersTest.php
index 259226c402..09f50753ae 100644
--- a/tests/integration/API/JSON/v1/SendingTaskSubscribersTest.php
+++ b/tests/integration/API/JSON/v1/SendingTaskSubscribersTest.php
@@ -15,7 +15,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SendingTaskSubscribersTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->endpoint = ContainerWrapper::getInstance()->get(SendingTaskSubscribers::class);
     $this->newsletter_id = Newsletter::createOrUpdate([
@@ -66,7 +66,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
     ]);
   }
 
-  function testListingReturnsErrorIfMissingNewsletter() {
+  public function testListingReturnsErrorIfMissingNewsletter() {
     $res = $this->endpoint->listing([
       'sort_by' => 'created_at',
       'params' => ['id' => $this->newsletter_id + 1],
@@ -76,7 +76,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
       ->equals('This email has not been sent yet.');
   }
 
-  function testListingReturnsErrorIfNewsletterNotBeingSent() {
+  public function testListingReturnsErrorIfNewsletterNotBeingSent() {
     $newsletter = Newsletter::createOrUpdate([
       'type' => Newsletter::TYPE_STANDARD,
       'subject' => 'Draft',
@@ -91,7 +91,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
       ->equals('This email has not been sent yet.');
   }
 
-  function testItReturnsListing() {
+  public function testItReturnsListing() {
     $sent_subscriber_status = [
       'error' => '',
       'failed' => 0,
@@ -165,7 +165,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
     ]);
   }
 
-  function testResendReturnsErrorIfWrongData() {
+  public function testResendReturnsErrorIfWrongData() {
     $res = $this->endpoint->resend([
       'taskId' => $this->task_id + 1,
       'subscriberId' => $this->sent_subscriber->id,
@@ -183,7 +183,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
       ->equals('Failed sending task not found!');
   }
 
-  function testItCanResend() {
+  public function testItCanResend() {
     $res = $this->endpoint->resend([
       'taskId' => $this->task_id,
       'subscriberId' => $this->failed_subscriber->id,
@@ -204,7 +204,7 @@ class SendingTaskSubscribersTest extends \MailPoetTest {
     expect($newsletter->status)->equals(Newsletter::STATUS_SENDING);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/API/JSON/v1/ServicesTest.php b/tests/integration/API/JSON/v1/ServicesTest.php
index 4102cb2861..40d7428197 100644
--- a/tests/integration/API/JSON/v1/ServicesTest.php
+++ b/tests/integration/API/JSON/v1/ServicesTest.php
@@ -16,14 +16,14 @@ class ServicesTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->services_endpoint = $this->di_container->get(Services::class);
     $this->data = ['key' => '1234567890abcdef'];
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItRespondsWithErrorIfSPFCheckFails() {
+  public function testItRespondsWithErrorIfSPFCheckFails() {
     $email = 'spf_test@example.com';
     $this->settings->set('sender.address', $email);
 
@@ -39,7 +39,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->meta['sender_address'])->equals($email);
   }
 
-  function testItRespondsWithSuccessIfSPFCheckPasses() {
+  public function testItRespondsWithSuccessIfSPFCheckPasses() {
     $spf_check = $this->make(
       SPFCheck::class,
       ['checkSPFRecord' => true],
@@ -51,13 +51,13 @@ class ServicesTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_OK);
   }
 
-  function testItRespondsWithErrorIfNoMSSKeyIsGiven() {
+  public function testItRespondsWithErrorIfNoMSSKeyIsGiven() {
     $response = $this->di_container->get(Services::class)->checkMSSKey(['key' => '']);
     expect($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
     expect($response->errors[0]['message'])->equals('Please specify a key.');
   }
 
-  function testItRespondsWithSuccessIfMSSKeyIsValid() {
+  public function testItRespondsWithSuccessIfMSSKeyIsValid() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -72,7 +72,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_OK);
   }
 
-  function testItRespondsWithErrorIfMSSKeyIsInvalid() {
+  public function testItRespondsWithErrorIfMSSKeyIsInvalid() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -86,7 +86,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
   }
 
-  function testItRespondsWithErrorIfMSSKeyIsExpiring() {
+  public function testItRespondsWithErrorIfMSSKeyIsExpiring() {
     $date = new \DateTime;
     $bridge = $this->make(
       new Bridge(),
@@ -107,7 +107,7 @@ class ServicesTest extends \MailPoetTest {
       ->contains($date->format($services_endpoint->date_time->getDateFormat()));
   }
 
-  function testItRespondsWithErrorIfServiceIsUnavailableDuringMSSCheck() {
+  public function testItRespondsWithErrorIfServiceIsUnavailableDuringMSSCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -127,7 +127,7 @@ class ServicesTest extends \MailPoetTest {
     );
   }
 
-  function testItRespondsWithErrorIfServiceDidNotReturnAResponseCodeDuringMSSCheck() {
+  public function testItRespondsWithErrorIfServiceDidNotReturnAResponseCodeDuringMSSCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -147,7 +147,7 @@ class ServicesTest extends \MailPoetTest {
     );
   }
 
-  function testItPrintsErrorCodeIfServiceReturnedAnUnexpectedResponseCodeDuringMSSCheck() {
+  public function testItPrintsErrorCodeIfServiceReturnedAnUnexpectedResponseCodeDuringMSSCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -163,7 +163,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->contains('404');
   }
 
-  function testItRespondsWithErrorIfMSSCheckThrowsAnException() {
+  public function testItRespondsWithErrorIfMSSCheckThrowsAnException() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -181,13 +181,13 @@ class ServicesTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('test');
   }
 
-  function testItRespondsWithErrorIfNoPremiumKeyIsGiven() {
+  public function testItRespondsWithErrorIfNoPremiumKeyIsGiven() {
     $response = $response = $this->di_container->get(Services::class)->checkPremiumKey(['key' => '']);
     expect($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
     expect($response->errors[0]['message'])->equals('Please specify a key.');
   }
 
-  function testItRespondsWithSuccessIfPremiumKeyIsValid() {
+  public function testItRespondsWithSuccessIfPremiumKeyIsValid() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -205,7 +205,7 @@ class ServicesTest extends \MailPoetTest {
     }
   }
 
-  function testItRespondsWithErrorIfPremiumKeyIsInvalid() {
+  public function testItRespondsWithErrorIfPremiumKeyIsInvalid() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -220,7 +220,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
   }
 
-  function testItRespondsWithErrorIfPremiumKeyIsUsed() {
+  public function testItRespondsWithErrorIfPremiumKeyIsUsed() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -235,7 +235,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
   }
 
-  function testItRespondsWithErrorIfPremiumKeyIsExpiring() {
+  public function testItRespondsWithErrorIfPremiumKeyIsExpiring() {
     $date = new \DateTime;
     $bridge = $this->make(
       new Bridge(),
@@ -256,7 +256,7 @@ class ServicesTest extends \MailPoetTest {
       ->contains($date->format($services_endpoint->date_time->getDateFormat()));
   }
 
-  function testItRespondsWithErrorIfServiceIsUnavailableDuringPremiumCheck() {
+  public function testItRespondsWithErrorIfServiceIsUnavailableDuringPremiumCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -276,7 +276,7 @@ class ServicesTest extends \MailPoetTest {
     );
   }
 
-  function testItRespondsWithErrorIfServiceDidNotReturnAResponseCodeDuringPremiumCheck() {
+  public function testItRespondsWithErrorIfServiceDidNotReturnAResponseCodeDuringPremiumCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -296,7 +296,7 @@ class ServicesTest extends \MailPoetTest {
     );
   }
 
-  function testItPrintsErrorCodeIfServiceReturnedAnUnexpectedResponseCodeDuringPremiumCheck() {
+  public function testItPrintsErrorCodeIfServiceReturnedAnUnexpectedResponseCodeDuringPremiumCheck() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -312,7 +312,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->contains('404');
   }
 
-  function testItRespondsWithErrorIfPremiumCheckThrowsAnException() {
+  public function testItRespondsWithErrorIfPremiumCheckThrowsAnException() {
     $bridge = $this->make(
       new Bridge(),
       [
@@ -330,7 +330,7 @@ class ServicesTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('test');
   }
 
-  function testItRespondsWithPublicIdForMSS() {
+  public function testItRespondsWithPublicIdForMSS() {
     $fake_public_id = 'a-fake-public_id';
     $this->settings->delete('public_id');
     $this->settings->delete('new_public_id');
@@ -354,7 +354,7 @@ class ServicesTest extends \MailPoetTest {
     expect($this->settings->get('new_public_id'))->equals('true');
   }
 
-  function testItRespondsWithoutPublicIdForMSS() {
+  public function testItRespondsWithoutPublicIdForMSS() {
     $this->settings->delete('public_id');
     $this->settings->delete('new_public_id');
 
@@ -374,7 +374,7 @@ class ServicesTest extends \MailPoetTest {
     expect($this->settings->get('new_public_id', null))->null();
   }
 
-  function testItRespondsWithPublicIdForPremium() {
+  public function testItRespondsWithPublicIdForPremium() {
     $fake_public_id = 'another-fake-public_id';
     $this->settings->delete('public_id');
     $this->settings->delete('new_public_id');
@@ -398,7 +398,7 @@ class ServicesTest extends \MailPoetTest {
     expect($this->settings->get('new_public_id'))->equals('true');
   }
 
-  function testItRespondsWithoutPublicIdForPremium() {
+  public function testItRespondsWithoutPublicIdForPremium() {
     $this->settings->delete('public_id');
     $this->settings->delete('new_public_id');
 
diff --git a/tests/integration/API/JSON/v1/SettingsTest.php b/tests/integration/API/JSON/v1/SettingsTest.php
index 70bc233b3b..2a1f296d28 100644
--- a/tests/integration/API/JSON/v1/SettingsTest.php
+++ b/tests/integration/API/JSON/v1/SettingsTest.php
@@ -24,7 +24,7 @@ class SettingsTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     $this->settings = SettingsController::getInstance();
@@ -37,7 +37,7 @@ class SettingsTest extends \MailPoetTest {
     );
   }
 
-  function testItCanGetSettings() {
+  public function testItCanGetSettings() {
     $response = $this->endpoint->get();
     expect($response->status)->equals(APIResponse::STATUS_OK);
 
@@ -51,7 +51,7 @@ class SettingsTest extends \MailPoetTest {
     expect($response->data)->equals($this->settings->getAllDefaults());
   }
 
-  function testItCanSetSettings() {
+  public function testItCanSetSettings() {
     $new_settings = [
       'some' => [
         'setting' => [
@@ -82,7 +82,7 @@ class SettingsTest extends \MailPoetTest {
     expect($response->data['some']['new_setting'])->true();
   }
 
-  function testItSchedulesInactiveSubscribersCheckIfIntervalSettingChanges() {
+  public function testItSchedulesInactiveSubscribersCheckIfIntervalSettingChanges() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 30);
     $settings = ['deactivate_subscriber_after_inactive_days' => 30];
     $this->endpoint->set($settings);
@@ -99,7 +99,7 @@ class SettingsTest extends \MailPoetTest {
     expect($task->scheduled_at)->lessThan(Carbon::now());
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/API/JSON/v1/SetupTest.php b/tests/integration/API/JSON/v1/SetupTest.php
index a71b1fbed2..b684189f2f 100644
--- a/tests/integration/API/JSON/v1/SetupTest.php
+++ b/tests/integration/API/JSON/v1/SetupTest.php
@@ -16,13 +16,13 @@ use MailPoet\Subscription\Captcha;
 use MailPoet\WP\Functions as WPFunctions;
 
 class SetupTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $settings = SettingsController::getInstance();
     $settings->set('signup_confirmation.enabled', false);
   }
 
-  function testItCanReinstall() {
+  public function testItCanReinstall() {
     $wp = Stub::make(new WPFunctions, [
       'doAction' => asCallable([WPHooksHelper::class, 'doAction']),
     ]);
@@ -54,7 +54,7 @@ class SetupTest extends \MailPoetTest {
     expect(WPHooksHelper::isActionDone($hook_name))->true();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/API/JSON/v1/SubscribersTest.php b/tests/integration/API/JSON/v1/SubscribersTest.php
index b8e2443038..b145539627 100644
--- a/tests/integration/API/JSON/v1/SubscribersTest.php
+++ b/tests/integration/API/JSON/v1/SubscribersTest.php
@@ -46,7 +46,7 @@ class SubscribersTest extends \MailPoetTest {
   /** @var CaptchaSession */
   private $captcha_session;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cleanup();
     $container = ContainerWrapper::getInstance();
@@ -111,7 +111,7 @@ class SubscribersTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanGetASubscriber() {
+  public function testItCanGetASubscriber() {
     $response = $this->endpoint->get(['id' => 'not_an_id']);
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
     expect($response->errors[0]['message'])->equals(
@@ -134,7 +134,7 @@ class SubscribersTest extends \MailPoetTest {
     );
   }
 
-  function testItCanSaveANewSubscriber() {
+  public function testItCanSaveANewSubscriber() {
     $valid_data = [
       'email' => 'raul.doe@mailpoet.com',
       'first_name' => 'Raul',
@@ -175,7 +175,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($subscriber->source)->equals('administrator');
   }
 
-  function testItCanSaveAnExistingSubscriber() {
+  public function testItCanSaveAnExistingSubscriber() {
     $subscriber_data = $this->subscriber_2->asArray();
     unset($subscriber_data['created_at']);
     $subscriber_data['segments'] = [$this->segment_1->id];
@@ -190,7 +190,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->data['source'])->equals('api');
   }
 
-  function testItCanRemoveListsFromAnExistingSubscriber() {
+  public function testItCanRemoveListsFromAnExistingSubscriber() {
     $subscriber_data = $this->subscriber_2->asArray();
     unset($subscriber_data['created_at']);
     unset($subscriber_data['segments']);
@@ -203,7 +203,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($this->subscriber_2->segments()->findArray())->count(0);
   }
 
-  function testItCanRestoreASubscriber() {
+  public function testItCanRestoreASubscriber() {
     $this->subscriber_1->trash();
 
     $trashed_subscriber = Subscriber::findOne($this->subscriber_1->id);
@@ -218,7 +218,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanTrashASubscriber() {
+  public function testItCanTrashASubscriber() {
     $response = $this->endpoint->trash(['id' => $this->subscriber_2->id]);
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->data)->equals(
@@ -228,14 +228,14 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanDeleteASubscriber() {
+  public function testItCanDeleteASubscriber() {
     $response = $this->endpoint->delete(['id' => $this->subscriber_1->id]);
     expect($response->data)->isEmpty();
     expect($response->status)->equals(APIResponse::STATUS_OK);
     expect($response->meta['count'])->equals(1);
   }
 
-  function testItCanFilterListing() {
+  public function testItCanFilterListing() {
     // filter by non existing segment
     $response = $this->endpoint->listing([
       'filter' => [
@@ -267,7 +267,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->data[0]['email'])->equals($this->subscriber_2->email);
   }
 
-  function testItCanAddSegmentsUsingHooks() {
+  public function testItCanAddSegmentsUsingHooks() {
     $add_segment = function() {
       return 'segment';
     };
@@ -280,7 +280,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->meta['filters']['segment'])->equals('segment');
   }
 
-  function testItCanSearchListing() {
+  public function testItCanSearchListing() {
     $new_subscriber = Subscriber::createOrUpdate([
       'email' => 'search.me@find.me',
       'first_name' => 'Billy Bob',
@@ -316,7 +316,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->data[0]['email'])->equals($new_subscriber->email);
   }
 
-  function testItCanGroupListing() {
+  public function testItCanGroupListing() {
     $subscribed_group = $this->endpoint->listing([
       'group' => Subscriber::STATUS_SUBSCRIBED,
     ]);
@@ -355,7 +355,7 @@ class SubscribersTest extends \MailPoetTest {
     );
   }
 
-  function testItCorrectSubscriptionStatus() {
+  public function testItCorrectSubscriptionStatus() {
     $segment = Segment::createOrUpdate(['name' => 'Segment185245']);
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'third@example.com',
@@ -379,7 +379,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->data[0]['status'])->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItCanSortAndLimitListing() {
+  public function testItCanSortAndLimitListing() {
     // get 1st page (limit items per page to 1)
     $response = $this->endpoint->listing([
       'limit' => 1,
@@ -408,7 +408,7 @@ class SubscribersTest extends \MailPoetTest {
     );
   }
 
-  function testItCanBulkDeleteSelectionOfSubscribers() {
+  public function testItCanBulkDeleteSelectionOfSubscribers() {
     $deletable_subscriber = Subscriber::createOrUpdate([
       'email' => 'to.be.removed@mailpoet.com',
     ]);
@@ -439,7 +439,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($is_deletable_subscriber_deleted)->true();
   }
 
-  function testItCanBulkDeleteSubscribers() {
+  public function testItCanBulkDeleteSubscribers() {
     $response = $this->endpoint->bulkAction([
       'action' => 'trash',
       'listing' => ['group' => 'all'],
@@ -462,7 +462,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->meta['count'])->equals(0);
   }
 
-  function testItCannotRunAnInvalidBulkAction() {
+  public function testItCannotRunAnInvalidBulkAction() {
     $response = $this->endpoint->bulkAction([
       'action' => 'invalidAction',
       'listing' => [],
@@ -471,7 +471,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->contains('has no method');
   }
 
-  function testItFailsWithEmailFilled() {
+  public function testItFailsWithEmailFilled() {
     $response = $this->endpoint->subscribe([
       'form_id' => $this->form->id,
       'email' => 'toto@mailpoet.com',
@@ -482,7 +482,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please leave the first field empty.');
   }
 
-  function testItCannotSubscribeWithoutFormID() {
+  public function testItCannotSubscribeWithoutFormID() {
     $response = $this->endpoint->subscribe([
       'form_field_ZW1haWw' => 'toto@mailpoet.com',
       // no form ID specified
@@ -492,7 +492,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please specify a valid form ID.');
   }
 
-  function testItCannotSubscribeWithoutSegmentsIfTheyAreSelectedByUser() {
+  public function testItCannotSubscribeWithoutSegmentsIfTheyAreSelectedByUser() {
     $response = $this->endpoint->subscribe([
       $this->obfuscatedEmail => 'toto@mailpoet.com',
       'form_id' => $this->form->id,
@@ -503,7 +503,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please select a list.');
   }
 
-  function testItCanSubscribe() {
+  public function testItCanSubscribe() {
     $response = $this->endpoint->subscribe([
       $this->obfuscatedEmail => 'toto@mailpoet.com',
       'form_id' => $this->form->id,
@@ -512,7 +512,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_OK);
   }
 
-  function testItCannotSubscribeWithoutReCaptchaWhenEnabled() {
+  public function testItCannotSubscribeWithoutReCaptchaWhenEnabled() {
     $this->settings->set('captcha', ['type' => Captcha::TYPE_RECAPTCHA]);
     $response = $this->endpoint->subscribe([
       $this->obfuscatedEmail => 'toto@mailpoet.com',
@@ -524,7 +524,7 @@ class SubscribersTest extends \MailPoetTest {
     $this->settings->set('captcha', []);
   }
 
-  function testItCannotSubscribeWithoutBuiltInCaptchaWhenEnabled() {
+  public function testItCannotSubscribeWithoutBuiltInCaptchaWhenEnabled() {
     $this->settings->set('captcha', ['type' => Captcha::TYPE_BUILTIN]);
     $email = 'toto@mailpoet.com';
     $subscriber = Subscriber::create();
@@ -541,7 +541,7 @@ class SubscribersTest extends \MailPoetTest {
     $this->settings->set('captcha', []);
   }
 
-  function testItCanSubscribeWithBuiltInCaptchaWhenEnabled() {
+  public function testItCanSubscribeWithBuiltInCaptchaWhenEnabled() {
     $this->settings->set('captcha', ['type' => Captcha::TYPE_BUILTIN]);
     $email = 'toto@mailpoet.com';
     $subscriber = Subscriber::create();
@@ -563,7 +563,7 @@ class SubscribersTest extends \MailPoetTest {
     $this->settings->set('captcha', []);
   }
 
-  function testItCannotSubscribeWithoutMandatoryCustomField() {
+  public function testItCannotSubscribeWithoutMandatoryCustomField() {
     $custom_field = CustomField::createOrUpdate([
       'name' => 'custom field',
       'type' => 'text',
@@ -589,7 +589,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_BAD_REQUEST);
   }
 
-  function testItCanSubscribeWithoutSegmentsIfTheyAreSelectedByAdmin() {
+  public function testItCanSubscribeWithoutSegmentsIfTheyAreSelectedByAdmin() {
     $form = $this->form->asArray();
     $form['settings']['segments_selected_by'] = 'admin';
     $this->form->settings = $form['settings'];
@@ -609,7 +609,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($subscriber_segments[1]['id'])->equals($form['settings']['segments'][1]);
   }
 
-  function testItCannotSubscribeIfFormHasNoSegmentsDefined() {
+  public function testItCannotSubscribeIfFormHasNoSegmentsDefined() {
     $form = $this->form->asArray();
     $form['settings']['segments_selected_by'] = 'admin';
     unset($form['settings']['segments']);
@@ -626,7 +626,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('Please select a list.');
   }
 
-  function testItCannotMassSubscribe() {
+  public function testItCannotMassSubscribe() {
     $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
 
     $this->endpoint->subscribe([
@@ -645,7 +645,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('You need to wait 1 minutes before subscribing again.');
   }
 
-  function testItCannotMassResubscribe() {
+  public function testItCannotMassResubscribe() {
     $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
 
     $this->endpoint->subscribe([
@@ -670,7 +670,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->errors[0]['message'])->equals('You need to wait 1 minutes before subscribing again.');
   }
 
-  function testItSchedulesWelcomeEmailNotificationWhenSubscriberIsAdded() {
+  public function testItSchedulesWelcomeEmailNotificationWhenSubscriberIsAdded() {
     $this->_createWelcomeNewsletter();
     $subscriber_data = [
       'email' => 'raul.doe@mailpoet.com',
@@ -685,7 +685,7 @@ class SubscribersTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(1);
   }
 
-  function testItSchedulesWelcomeEmailNotificationWhenExistedSubscriberIsUpdated() {
+  public function testItSchedulesWelcomeEmailNotificationWhenExistedSubscriberIsUpdated() {
     $this->_createWelcomeNewsletter();
     $subscriber_data = [
       'email' => 'raul.doe@mailpoet.com',
@@ -705,7 +705,7 @@ class SubscribersTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(1);
   }
 
-  function testItDoesNotSchedulesWelcomeEmailNotificationWhenNoNewSegmentIsAdded() {
+  public function testItDoesNotSchedulesWelcomeEmailNotificationWhenNoNewSegmentIsAdded() {
     $this->_createWelcomeNewsletter();
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'raul.doe@mailpoet.com',
@@ -731,7 +731,7 @@ class SubscribersTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItSendsConfirmationEmail() {
+  public function testItSendsConfirmationEmail() {
     $response = $this->endpoint->sendConfirmationEmail(['id' => 'non_existent']);
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
 
@@ -745,7 +745,7 @@ class SubscribersTest extends \MailPoetTest {
     expect($response->status)->equals(APIResponse::STATUS_NOT_FOUND);
   }
 
-  function testItKeepsSpecialSegmentsUnchangedAfterSaving() {
+  public function testItKeepsSpecialSegmentsUnchangedAfterSaving() {
     $wc_segment = Segment::createOrUpdate([
       'name' => 'WooCommerce Users',
       'type' => Segment::TYPE_WC_USERS,
@@ -806,7 +806,7 @@ class SubscribersTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanup();
   }
 
diff --git a/tests/integration/API/JSON/v1/UserFlagsTest.php b/tests/integration/API/JSON/v1/UserFlagsTest.php
index 5a7eab45c9..9346e29af8 100644
--- a/tests/integration/API/JSON/v1/UserFlagsTest.php
+++ b/tests/integration/API/JSON/v1/UserFlagsTest.php
@@ -18,7 +18,7 @@ class UserFlagsTest extends \MailPoetTest {
   /** @var UserFlagsController */
   private $user_flags;
 
-  function _before() {
+  public function _before() {
     $this->cleanup();
     $this->user_flags = Stub::make(UserFlagsController::class, [
       'user_flags_repository' => $this->di_container->get(UserFlagsRepository::class),
@@ -26,12 +26,12 @@ class UserFlagsTest extends \MailPoetTest {
         'flag_1' => 'default_value_1',
         'flag_2' => 'default_value_2',
       ],
-    ]);    
+    ]);
     $this->user_flags->set('flag_1', 'value_1');
     $this->endpoint = new UserFlags($this->user_flags);
   }
 
-  function testItCanSetUserFlags() {
+  public function testItCanSetUserFlags() {
     $new_flags = [
       'flag_1' => 'new_value_1',
       'flag_3' => 'new_value_3',
@@ -56,7 +56,7 @@ class UserFlagsTest extends \MailPoetTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanup();
   }
 
diff --git a/tests/integration/API/JSON/v1/WoocommerceSettingsTest.php b/tests/integration/API/JSON/v1/WoocommerceSettingsTest.php
index a519a5b2c4..a55c3d9067 100644
--- a/tests/integration/API/JSON/v1/WoocommerceSettingsTest.php
+++ b/tests/integration/API/JSON/v1/WoocommerceSettingsTest.php
@@ -14,11 +14,11 @@ class WoocommerceSettingsTest extends \MailPoetTest {
   /** @var WPFunctions */
   private $wp;
 
-  function _before() {
+  public function _before() {
     $this->wp = new WPFunctions();
     $this->endpoint = new WoocommerceSettings($this->wp);
   }
-  function testItCanSetSettings() {
+  public function testItCanSetSettings() {
     $this->wp->updateOption('woocommerce_email_base_color', '#ffffff');
     $response = $this->endpoint->set([
       'woocommerce_email_base_color' => '#aaaaaa',
@@ -27,7 +27,7 @@ class WoocommerceSettingsTest extends \MailPoetTest {
     expect($this->wp->getOption('woocommerce_email_base_color'))->equals('#aaaaaa');
   }
 
-  function testItDoesNotSetUnallowedSettings() {
+  public function testItDoesNotSetUnallowedSettings() {
     $response = $this->endpoint->set([
       'mailpoet_some_none_exting_option' => 'some value',
     ]);
diff --git a/tests/integration/API/MP/APITest.php b/tests/integration/API/MP/APITest.php
index f4479d2a69..e10a2a59f7 100644
--- a/tests/integration/API/MP/APITest.php
+++ b/tests/integration/API/MP/APITest.php
@@ -32,7 +32,7 @@ class APITest extends \MailPoetTest {
     );
   }
 
-  function testItReturnsDefaultSubscriberFields() {
+  public function testItReturnsDefaultSubscriberFields() {
     $response = $this->getApi()->getSubscriberFields();
 
     expect($response)->contains([
@@ -61,7 +61,7 @@ class APITest extends \MailPoetTest {
     ]);
   }
 
-  function testItReturnsCustomFields() {
+  public function testItReturnsCustomFields() {
     $custom_field1 = CustomField::createOrUpdate([
       'name' => 'text custom field',
       'type' => CustomField::TYPE_TEXT,
@@ -94,7 +94,7 @@ class APITest extends \MailPoetTest {
     ]);
   }
 
-  function testItDoesNotSubscribeMissingSubscriberToLists() {
+  public function testItDoesNotSubscribeMissingSubscriberToLists() {
     try {
       $this->getApi()->subscribeToLists(false, [1,2,3]);
       $this->fail('Subscriber does not exist exception should have been thrown.');
@@ -103,7 +103,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotSubscribeSubscriberToMissingLists() {
+  public function testItDoesNotSubscribeSubscriberToMissingLists() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -123,7 +123,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotSubscribeSubscriberToWPUsersList() {
+  public function testItDoesNotSubscribeSubscriberToWPUsersList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -141,7 +141,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotSubscribeSubscriberToWooCommerceCustomersList() {
+  public function testItDoesNotSubscribeSubscriberToWooCommerceCustomersList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -159,7 +159,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotSubscribeSubscriberToListsWhenOneOrMoreListsAreMissing() {
+  public function testItDoesNotSubscribeSubscriberToListsWhenOneOrMoreListsAreMissing() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -185,7 +185,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItUsesMultipleListsSubscribeMethodWhenSubscribingToSingleList() {
+  public function testItUsesMultipleListsSubscribeMethodWhenSubscribingToSingleList() {
     // subscribing to single list = converting list ID to an array and using
     // multiple lists subscription method
     $API = Stub::make($this->getApi(), [
@@ -204,7 +204,7 @@ class APITest extends \MailPoetTest {
     );
   }
 
-  function testItSubscribesSubscriberToMultipleLists() {
+  public function testItSubscribesSubscriberToMultipleLists() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -228,7 +228,7 @@ class APITest extends \MailPoetTest {
     expect($result['subscriptions'][0]['segment_id'])->equals($segment->id);
   }
 
-  function testItSendsConfirmationEmailToASubscriberWhenBeingAddedToList() {
+  public function testItSendsConfirmationEmailToASubscriberWhenBeingAddedToList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->status = Subscriber::STATUS_UNCONFIRMED;
@@ -264,7 +264,7 @@ class APITest extends \MailPoetTest {
     expect($sent)->equals(false);
   }
 
-  function testItSendsNotifiationEmailWhenBeingAddedToList() {
+  public function testItSendsNotifiationEmailWhenBeingAddedToList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->status = Subscriber::STATUS_SUBSCRIBED;
@@ -300,7 +300,7 @@ class APITest extends \MailPoetTest {
     $API->subscribeToLists($subscriber->email, $segments, ['send_confirmation_email' => false, 'skip_subscriber_notification' => false]);
   }
 
-  function testItSubscribesSubscriberWithEmailIdentifier() {
+  public function testItSubscribesSubscriberWithEmailIdentifier() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -316,7 +316,7 @@ class APITest extends \MailPoetTest {
     expect($result['subscriptions'][0]['segment_id'])->equals($segment->id);
   }
 
-  function testItSchedulesWelcomeNotificationByDefaultAfterSubscriberSubscriberToLists() {
+  public function testItSchedulesWelcomeNotificationByDefaultAfterSubscriberSubscriberToLists() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'subscribeToLists',
@@ -336,7 +336,7 @@ class APITest extends \MailPoetTest {
     $API->subscribeToLists($subscriber->id, [$segment->id], ['skip_subscriber_notification' => true]);
   }
 
-  function testItDoesNotScheduleWelcomeNotificationAfterSubscribingSubscriberToListsIfStatusIsNotSubscribed() {
+  public function testItDoesNotScheduleWelcomeNotificationAfterSubscribingSubscriberToListsIfStatusIsNotSubscribed() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'subscribeToLists',
@@ -355,7 +355,7 @@ class APITest extends \MailPoetTest {
     $API->subscribeToLists($subscriber->id, [$segment->id], ['skip_subscriber_notification' => true]);
   }
 
-  function testItDoesNotScheduleWelcomeNotificationAfterSubscribingSubscriberToListsWhenDisabledByOption() {
+  public function testItDoesNotScheduleWelcomeNotificationAfterSubscribingSubscriberToListsWhenDisabledByOption() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'subscribeToLists',
@@ -376,7 +376,7 @@ class APITest extends \MailPoetTest {
     $API->subscribeToLists($subscriber->id, [$segment->id], $options);
   }
 
-  function testItGetsSegments() {
+  public function testItGetsSegments() {
     $segment = Segment::createOrUpdate(
       [
         'name' => 'Default',
@@ -388,7 +388,7 @@ class APITest extends \MailPoetTest {
     expect($result[0]['id'])->equals($segment->id);
   }
 
-  function testItExcludesWPUsersAndWooCommerceCustomersSegmentsWhenGettingSegments() {
+  public function testItExcludesWPUsersAndWooCommerceCustomersSegmentsWhenGettingSegments() {
     $default_segment = Segment::createOrUpdate(
       [
         'name' => 'Default',
@@ -412,7 +412,7 @@ class APITest extends \MailPoetTest {
     expect($result[0]['id'])->equals($default_segment->id);
   }
 
-  function testItRequiresEmailAddressToAddSubscriber() {
+  public function testItRequiresEmailAddressToAddSubscriber() {
     try {
       $this->getApi()->addSubscriber([]);
       $this->fail('Subscriber email address required exception should have been thrown.');
@@ -422,7 +422,7 @@ class APITest extends \MailPoetTest {
   }
 
 
-  function testItOnlyAcceptsWhitelistedProperties() {
+  public function testItOnlyAcceptsWhitelistedProperties() {
     $subscriber = [
       'email' => 'test-ignore-status@example.com',
       'first_name' => '',
@@ -434,7 +434,7 @@ class APITest extends \MailPoetTest {
     expect($result['status'])->equals('unconfirmed');
   }
 
-  function testItDoesNotAddExistingSubscriber() {
+  public function testItDoesNotAddExistingSubscriber() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -446,7 +446,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItThrowsExceptionWhenSubscriberCannotBeAdded() {
+  public function testItThrowsExceptionWhenSubscriberCannotBeAdded() {
     $subscriber = [
       'email' => 'test', // invalid email
     ];
@@ -460,7 +460,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItAddsSubscriber() {
+  public function testItAddsSubscriber() {
     $custom_field = CustomField::create();
     $custom_field->name = 'test custom field';
     $custom_field->type = CustomField::TYPE_TEXT;
@@ -481,7 +481,7 @@ class APITest extends \MailPoetTest {
     expect(strlen($result['unsubscribe_token']))->equals(15);
   }
 
-  function testItAllowsToOverrideSubscriberIPAddress() {
+  public function testItAllowsToOverrideSubscriberIPAddress() {
     $subscriber = [
       'email' => 'test-ip-2@example.com',
       'subscribed_ip' => '1.2.3.4',
@@ -491,7 +491,7 @@ class APITest extends \MailPoetTest {
     expect($result['subscribed_ip'])->equals($subscriber['subscribed_ip']);
   }
 
-  function testItChecksForMandatoryCustomFields() {
+  public function testItChecksForMandatoryCustomFields() {
     CustomField::createOrUpdate([
       'name' => 'custom field',
       'type' => 'text',
@@ -506,7 +506,7 @@ class APITest extends \MailPoetTest {
     $this->getApi()->addSubscriber($subscriber);
   }
 
-  function testItSubscribesToSegmentsWhenAddingSubscriber() {
+  public function testItSubscribesToSegmentsWhenAddingSubscriber() {
     $segment = Segment::createOrUpdate(
       [
         'name' => 'Default',
@@ -523,7 +523,7 @@ class APITest extends \MailPoetTest {
     expect($result['subscriptions'][0]['segment_id'])->equals($segment->id);
   }
 
-  function testItSchedulesWelcomeNotificationByDefaultAfterAddingSubscriber() {
+  public function testItSchedulesWelcomeNotificationByDefaultAfterAddingSubscriber() {
     $settings = SettingsController::getInstance();
     $settings->set('signup_confirmation.enabled', false);
     $API = Stub::makeEmptyExcept(
@@ -541,7 +541,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments);
   }
 
-  function testItThrowsIfWelcomeEmailFails() {
+  public function testItThrowsIfWelcomeEmailFails() {
     $settings = SettingsController::getInstance();
     $settings->set('signup_confirmation.enabled', false);
     $task = ScheduledTask::create();
@@ -572,7 +572,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments, ['schedule_welcome_email' => true, 'send_confirmation_email' => false]);
   }
 
-  function testItDoesNotScheduleWelcomeNotificationAfterAddingSubscriberIfStatusIsNotSubscribed() {
+  public function testItDoesNotScheduleWelcomeNotificationAfterAddingSubscriberIfStatusIsNotSubscribed() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'addSubscriber',
@@ -590,7 +590,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments);
   }
 
-  function testItDoesNotScheduleWelcomeNotificationAfterAddingSubscriberWhenDisabledByOption() {
+  public function testItDoesNotScheduleWelcomeNotificationAfterAddingSubscriberWhenDisabledByOption() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'addSubscriber',
@@ -608,7 +608,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments, $options);
   }
 
-  function testByDefaultItSendsConfirmationEmailAfterAddingSubscriber() {
+  public function testByDefaultItSendsConfirmationEmailAfterAddingSubscriber() {
     $API = $this->makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'addSubscriber',
@@ -628,7 +628,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments);
   }
 
-  function testItThrowsWhenConfirmationEmailFailsToSend() {
+  public function testItThrowsWhenConfirmationEmailFailsToSend() {
     $confirmation_mailer = $this->createMock(ConfirmationEmailMailer::class);
     $confirmation_mailer->expects($this->once())
       ->method('sendConfirmationEmail')
@@ -653,7 +653,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, [$segment->id], ['send_confirmation_email' => true]);
   }
 
-  function testItDoesNotSendConfirmationEmailAfterAddingSubscriberWhenOptionIsSet() {
+  public function testItDoesNotSendConfirmationEmailAfterAddingSubscriberWhenOptionIsSet() {
     $API = Stub::makeEmptyExcept(
       \MailPoet\API\MP\v1\API::class,
       'addSubscriber',
@@ -670,7 +670,7 @@ class APITest extends \MailPoetTest {
     $API->addSubscriber($subscriber, $segments, $options);
   }
 
-  function testItRequiresNameToAddList() {
+  public function testItRequiresNameToAddList() {
     try {
       $this->getApi()->addList([]);
       $this->fail('List name required exception should have been thrown.');
@@ -679,7 +679,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesOnlySaveWhiteListedPropertiesWhenAddingList() {
+  public function testItDoesOnlySaveWhiteListedPropertiesWhenAddingList() {
     $result = $this->getApi()->addList([
       'name' => 'Test segment123',
       'description' => 'Description',
@@ -691,7 +691,7 @@ class APITest extends \MailPoetTest {
     expect($result['type'])->equals('default');
   }
 
-  function testItDoesNotAddExistingList() {
+  public function testItDoesNotAddExistingList() {
     $segment = Segment::create();
     $segment->name = 'Test segment';
     $segment->save();
@@ -703,7 +703,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItAddsList() {
+  public function testItAddsList() {
     $segment = [
       'name' => 'Test segment',
     ];
@@ -713,7 +713,7 @@ class APITest extends \MailPoetTest {
     expect($result['name'])->equals($segment['name']);
   }
 
-  function testItDoesNotUnsubscribeMissingSubscriberFromLists() {
+  public function testItDoesNotUnsubscribeMissingSubscriberFromLists() {
     try {
       $this->getApi()->unsubscribeFromLists(false, [1,2,3]);
       $this->fail('Subscriber does not exist exception should have been thrown.');
@@ -722,7 +722,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotUnsubscribeSubscriberFromMissingLists() {
+  public function testItDoesNotUnsubscribeSubscriberFromMissingLists() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -742,7 +742,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotUnsubscribeSubscriberFromListsWhenOneOrMoreListsAreMissing() {
+  public function testItDoesNotUnsubscribeSubscriberFromListsWhenOneOrMoreListsAreMissing() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -768,7 +768,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotUnsubscribeSubscriberFromWPUsersList() {
+  public function testItDoesNotUnsubscribeSubscriberFromWPUsersList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -786,7 +786,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotUnsubscribeSubscriberFromWooCommerceCustomersList() {
+  public function testItDoesNotUnsubscribeSubscriberFromWooCommerceCustomersList() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -804,7 +804,7 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function testItUsesMultipleListsUnsubscribeMethodWhenUnsubscribingFromSingleList() {
+  public function testItUsesMultipleListsUnsubscribeMethodWhenUnsubscribingFromSingleList() {
     // unsubscribing from single list = converting list ID to an array and using
     // multiple lists unsubscribe method
     $API = Stub::make(\MailPoet\API\MP\v1\API::class, [
@@ -822,7 +822,7 @@ class APITest extends \MailPoetTest {
     );
   }
 
-  function testItUnsubscribesSubscriberFromMultipleLists() {
+  public function testItUnsubscribesSubscriberFromMultipleLists() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -847,7 +847,7 @@ class APITest extends \MailPoetTest {
     expect($result['subscriptions'][0]['status'])->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItGetsSubscriber() {
+  public function testItGetsSubscriber() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -873,12 +873,12 @@ class APITest extends \MailPoetTest {
     }
   }
 
-  function _before() {
+  public function _before() {
     $settings = SettingsController::getInstance();
     $settings->set('signup_confirmation.enabled', true);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . CustomField::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
diff --git a/tests/integration/Analytics/AnalyticsTest.php b/tests/integration/Analytics/AnalyticsTest.php
index ff2f0f43eb..b7701052ed 100644
--- a/tests/integration/Analytics/AnalyticsTest.php
+++ b/tests/integration/Analytics/AnalyticsTest.php
@@ -19,7 +19,7 @@ class AnalyticsTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->analytics = new Analytics(
@@ -30,22 +30,22 @@ class AnalyticsTest extends \MailPoetTest {
     remove_all_filters(Analytics::ANALYTICS_FILTER);
   }
 
-  function testIsEnabledReturnsTrueIfSettingEnabled() {
+  public function testIsEnabledReturnsTrueIfSettingEnabled() {
     $this->settings->set('analytics', ['enabled' => '1']);
     expect($this->analytics->isEnabled())->true();
   }
 
-  function testIsEnabledReturnsFalseIfEmptySettings() {
+  public function testIsEnabledReturnsFalseIfEmptySettings() {
     $this->settings->set('analytics', []);
     expect($this->analytics->isEnabled())->false();
   }
 
-  function testIsEnabledReturnsFalseIfNotEnabled() {
+  public function testIsEnabledReturnsFalseIfNotEnabled() {
     $this->settings->set('analytics', ['enabled' => '']);
     expect($this->analytics->isEnabled())->false();
   }
 
-  function testGetDataIfSettingsIsDisabled() {
+  public function testGetDataIfSettingsIsDisabled() {
     $reporter = Stub::makeEmpty(
       'MailPoet\Analytics\Reporter',
       [
@@ -59,7 +59,7 @@ class AnalyticsTest extends \MailPoetTest {
     expect($analytics->generateAnalytics())->null();
   }
 
-  function testGetDataIfSentRecently() {
+  public function testGetDataIfSentRecently() {
     $reporter = Stub::makeEmpty(
       'MailPoet\Analytics\Reporter',
       [
@@ -74,7 +74,7 @@ class AnalyticsTest extends \MailPoetTest {
     expect($analytics->generateAnalytics())->null();
   }
 
-  function testGetDataIfEnabledButNeverSent() {
+  public function testGetDataIfEnabledButNeverSent() {
     $data = [];
     $reporter = Stub::makeEmpty(
       'MailPoet\Analytics\Reporter',
@@ -92,7 +92,7 @@ class AnalyticsTest extends \MailPoetTest {
     expect($analytics->generateAnalytics())->equals(apply_filters(Analytics::ANALYTICS_FILTER, $data));
   }
 
-  function testGetDataIfEnabledAndSentLongTimeAgo() {
+  public function testGetDataIfEnabledAndSentLongTimeAgo() {
     $data = [];
     $reporter = Stub::makeEmpty(
       'MailPoet\Analytics\Reporter',
@@ -111,7 +111,7 @@ class AnalyticsTest extends \MailPoetTest {
     expect($analytics->generateAnalytics())->equals(apply_filters(Analytics::ANALYTICS_FILTER, $data));
   }
 
-  function testSetPublicId() {
+  public function testSetPublicId() {
     $fakePublicId = 'alk-ded-egrg-zaz-fvf-rtr-zdef';
 
     $this->settings->set('public_id', 'old-fake-public-id');
@@ -124,7 +124,7 @@ class AnalyticsTest extends \MailPoetTest {
     expect($this->settings->get(Analytics::SETTINGS_LAST_SENT_KEY, null))->null();
   }
 
-  function testIsPublicIdNew() {
+  public function testIsPublicIdNew() {
     $fakePublicId = 'alk-ded-egrg-zaz-fvf-rtr-zdef';
 
     $this->settings->set('public_id', 'old-fake-public-id');
diff --git a/tests/integration/AutomaticEmails/AutomaticEmailsTest.php b/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
index 5bc48689f3..2a160a2330 100644
--- a/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
+++ b/tests/integration/AutomaticEmails/AutomaticEmailsTest.php
@@ -5,11 +5,11 @@ namespace MailPoet\AutomaticEmails;
 use MailPoet\WP\Functions as WPFunctions;
 
 class AutomaticEmailsTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     $this->AM = new AutomaticEmails();
     $this->wp = new WPFunctions();
   }
-  function testItCanUnregisterAutomaticEmails() {
+  public function testItCanUnregisterAutomaticEmails() {
     $this->wp->addFilter('mailpoet_automatic_email_test1', function() {
       return [
         'slug' => 'email1',
@@ -33,7 +33,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItReturnsNullWhenThereAreNoRegisteredAutomaticEmails() {
+  public function testItReturnsNullWhenThereAreNoRegisteredAutomaticEmails() {
     $AM = $this->AM;
     $AM->unregisterAutomaticEmails();
     $AM->available_groups = [];
@@ -41,7 +41,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($AM->getAutomaticEmails())->null();
   }
 
-  function testItGetsAutomaticEmails() {
+  public function testItGetsAutomaticEmails() {
     $this->wp->addFilter('mailpoet_automatic_email_test1', function() {
       return [
         'slug' => 'email1',
@@ -83,12 +83,12 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('mailpoet_automatic_email_test2');
   }
 
-  function testItReturnsNullWhenGettingEmailBySlugAndThereAreNoRegisteredEmails() {
+  public function testItReturnsNullWhenGettingEmailBySlugAndThereAreNoRegisteredEmails() {
     expect($this->AM->getAutomaticEmailBySlug('some_slug'))->null();
 
   }
 
-  function testItReturnsNullWhenItCannotGetEmailBySlug() {
+  public function testItReturnsNullWhenItCannotGetEmailBySlug() {
     $this->wp->addFilter('mailpoet_automatic_email_test', function() {
       return [
         'slug' => 'email',
@@ -110,7 +110,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
 
-  function testItGetsEmailBySlug() {
+  public function testItGetsEmailBySlug() {
     $this->wp->addFilter('mailpoet_automatic_email_test1', function() {
       return [
         'slug' => 'email1',
@@ -150,11 +150,11 @@ class AutomaticEmailsTest extends \MailPoetTest {
   }
 
 
-  function testItReturnsNullWhenGettingEmailEventBySlugAndThereAreNoRegisteredEmails() {
+  public function testItReturnsNullWhenGettingEmailEventBySlugAndThereAreNoRegisteredEmails() {
     expect($this->AM->getAutomaticEmailEventBySlug('some_email', 'some_slug'))->null();
   }
 
-  function testItReturnsNullWhenItCannotGetEmailEventBySlug() {
+  public function testItReturnsNullWhenItCannotGetEmailEventBySlug() {
     $this->wp->addFilter('mailpoet_automatic_email_test', function() {
       return [
         'slug' => 'email',
@@ -176,7 +176,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
 
-  function testItGetsEmailEventBySlug() {
+  public function testItGetsEmailEventBySlug() {
     $this->wp->addFilter('mailpoet_automatic_email_test', function() {
       return [
         'slug' => 'email',
@@ -205,7 +205,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     $this->wp->removeAllFilters('mailpoet_automatic_email_test');
   }
 
-  function testItValidatesEmailDataFields() {
+  public function testItValidatesEmailDataFields() {
     // slug is missing
     $data = [
       'title' => true,
@@ -248,7 +248,7 @@ class AutomaticEmailsTest extends \MailPoetTest {
     expect($this->AM->validateAutomaticEmailDataFields($data))->true();
   }
 
-  function testItValidatesEmailEventsDataFields() {
+  public function testItValidatesEmailEventsDataFields() {
     // slug is missing
     $data = [
       [
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTrackerTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTrackerTest.php
index 06ca84604c..ed5fae98f6 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTrackerTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartPageVisitTrackerTest.php
@@ -24,7 +24,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
   /** @var AbandonedCartPageVisitTracker */
   private $page_visit_tracker;
 
-  function _before() {
+  public function _before() {
     $this->current_time = Carbon::now();
     Carbon::setTestNow($this->current_time);
 
@@ -43,17 +43,17 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
     $this->page_visit_tracker = new AbandonedCartPageVisitTracker($this->wp, $woo_commerce_helper_mock, new Cookies());
   }
 
-  function testItSetsTimestampWhenTrackingStarted() {
+  public function testItSetsTimestampWhenTrackingStarted() {
     $this->page_visit_tracker->startTracking();
     expect($this->session_store['mailpoet_last_visit_timestamp'])->same($this->current_time->getTimestamp());
   }
 
-  function testItDeletesTimestampWhenTrackingStopped() {
+  public function testItDeletesTimestampWhenTrackingStopped() {
     $this->page_visit_tracker->stopTracking();
     expect($this->session_store)->isEmpty();
   }
 
-  function testItTracks() {
+  public function testItTracks() {
     $this->wp->method('isAdmin')->willReturn(false);
     $this->wp->method('wpGetCurrentUser')->willReturn(
       $this->makeEmpty(WP_User::class, ['exists' => true])
@@ -70,7 +70,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
     expect($tracking_callback_executed)->true();
   }
 
-  function testItTracksByCookie() {
+  public function testItTracksByCookie() {
     $this->wp->method('isAdmin')->willReturn(false);
     $this->wp->method('wpGetCurrentUser')->willReturn(
       $this->makeEmpty(WP_User::class, ['exists' => false])
@@ -83,7 +83,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
     expect($this->session_store['mailpoet_last_visit_timestamp'])->same($this->current_time->getTimestamp());
   }
 
-  function testItDoesNotTrackWhenUserNotFound() {
+  public function testItDoesNotTrackWhenUserNotFound() {
     $this->wp->method('isAdmin')->willReturn(false);
     $this->wp->method('wpGetCurrentUser')->willReturn(
       $this->makeEmpty(WP_User::class, ['exists' => false])
@@ -95,7 +95,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
     expect($this->session_store['mailpoet_last_visit_timestamp'])->same($hour_ago_timestamp);
   }
 
-  function testItDoesNotTrackAdminPage() {
+  public function testItDoesNotTrackAdminPage() {
     $this->wp->method('isAdmin')->willReturn(true);
     $this->wp->method('wpGetCurrentUser')->willReturn(
       $this->makeEmpty(WP_User::class, ['exists' => true])
@@ -107,7 +107,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
     expect($this->session_store['mailpoet_last_visit_timestamp'])->same($hour_ago_timestamp);
   }
 
-  function testItDoesNotTrackMultipleTimesPerMinute() {
+  public function testItDoesNotTrackMultipleTimesPerMinute() {
     $ten_seconds_ago_timestamp = $this->current_time->getTimestamp() - 10;
     $this->session_store['mailpoet_last_visit_timestamp'] = $ten_seconds_ago_timestamp;
     $this->page_visit_tracker->trackVisit();
@@ -140,7 +140,7 @@ class AbandonedCartPageVisitTrackerTest extends \MailPoetTest {
       ->getMock();
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
   }
 }
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
index 6e7f03188a..6f7d51eebb 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/AbandonedCartTest.php
@@ -43,7 +43,7 @@ class AbandonedCartTest extends \MailPoetTest {
   /** @var AbandonedCartPageVisitTracker|MockObject */
   private $page_visit_tracker_mock;
 
-  function _before() {
+  public function _before() {
     $this->cleanup();
 
     $this->current_time = Carbon::createFromTimestamp((new WPFunctions())->currentTime('timestamp'));
@@ -65,14 +65,14 @@ class AbandonedCartTest extends \MailPoetTest {
     $this->page_visit_tracker_mock = $this->makeEmpty(AbandonedCartPageVisitTracker::class);
   }
 
-  function testItGetsEventDetails() {
+  public function testItGetsEventDetails() {
     $event = new AbandonedCart();
     $result = $event->getEventDetails();
     expect($result)->notEmpty();
     expect($result['slug'])->equals(AbandonedCart::SLUG);
   }
 
-  function testItRegistersWooCommerceCartEvents() {
+  public function testItRegistersWooCommerceCartEvents() {
     $abandoned_cart_email = $this->createAbandonedCartEmail();
 
     $registered_actions = [];
@@ -89,7 +89,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect($registered_actions)->contains('woocommerce_cart_item_restored');
   }
 
-  function testItRegistersPageVisitEvent() {
+  public function testItRegistersPageVisitEvent() {
     $abandoned_cart_email = $this->createAbandonedCartEmail();
 
     $registered_actions = [];
@@ -101,7 +101,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect($registered_actions)->contains('wp');
   }
 
-  function testItFindsUserByWordPressSession() {
+  public function testItFindsUserByWordPressSession() {
     $this->createNewsletter();
     $this->createSubscriberAsCurrentUser();
     $this->woo_commerce_cart_mock->method('is_empty')->willReturn(false);
@@ -113,7 +113,7 @@ class AbandonedCartTest extends \MailPoetTest {
   }
 
 
-  function testItFindsUserByCookie() {
+  public function testItFindsUserByCookie() {
     $this->createNewsletter();
     $subscriber = $this->createSubscriber();
 
@@ -134,7 +134,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect(ScheduledTask::findMany())->count(1);
   }
 
-  function testItSchedulesEmailWhenItemAddedToCart() {
+  public function testItSchedulesEmailWhenItemAddedToCart() {
     $this->createNewsletter();
     $this->createSubscriberAsCurrentUser();
 
@@ -153,7 +153,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect($scheduled_tasks[0]->scheduled_at)->same($expected_time->format('Y-m-d H:i:s'));
   }
 
-  function testItPostponesEmailWhenCartEdited() {
+  public function testItPostponesEmailWhenCartEdited() {
     $newsletter = $this->createNewsletter();
     $subscriber = $this->createSubscriberAsCurrentUser();
 
@@ -173,7 +173,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect($scheduled_tasks[0]->scheduled_at)->same($expected_time->format('Y-m-d H:i:s'));
   }
 
-  function testItCancelsEmailWhenCartEmpty() {
+  public function testItCancelsEmailWhenCartEmpty() {
     $newsletter = $this->createNewsletter();
     $subscriber = $this->createSubscriberAsCurrentUser();
 
@@ -194,7 +194,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItSchedulesNewEmailWhenEmailAlreadySent() {
+  public function testItSchedulesNewEmailWhenEmailAlreadySent() {
     $newsletter = $this->createNewsletter();
     $subscriber = $this->createSubscriberAsCurrentUser();
 
@@ -217,7 +217,7 @@ class AbandonedCartTest extends \MailPoetTest {
     expect($scheduled->scheduled_at)->same($expected_time->format('Y-m-d H:i:s'));
   }
 
-  function testItPostponesEmailWhenPageVisited() {
+  public function testItPostponesEmailWhenPageVisited() {
     $newsletter = $this->createNewsletter();
     $subscriber = $this->createSubscriberAsCurrentUser();
 
@@ -367,7 +367,7 @@ class AbandonedCartTest extends \MailPoetTest {
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions());
     Carbon::setTestNow();
     $this->cleanup();
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/FirstPurchaseTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/FirstPurchaseTest.php
index 7c07ab9309..22828d390d 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/FirstPurchaseTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/FirstPurchaseTest.php
@@ -24,11 +24,11 @@ use MailPoetVendor\Idiorm\ORM;
 require_once __DIR__ . '/../WooCommerceStubs/OrderDetails.php';
 
 class FirstPurchaseTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     WPFunctions::get()->removeAllFilters('mailpoet_newsletter_shortcode');
   }
 
-  function testItGetsEventDetails() {
+  public function testItGetsEventDetails() {
     $event = new FirstPurchase();
 
     $result = $event->getEventDetails();
@@ -36,7 +36,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result['slug'])->equals(FirstPurchase::SLUG);
   }
 
-  function testDateShortcodeHandlerReturnsShortcodeWhenItCannotDetectProperShortcode() {
+  public function testDateShortcodeHandlerReturnsShortcodeWhenItCannotDetectProperShortcode() {
     $event = new FirstPurchase();
     $shortcode = 'wrong shortcode';
 
@@ -44,7 +44,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals($shortcode);
   }
 
-  function testDateShortcodeHandlerReturnsShortcodeWhenQueueIsMissing() {
+  public function testDateShortcodeHandlerReturnsShortcodeWhenQueueIsMissing() {
     $event = new FirstPurchase();
     $shortcode = $event::ORDER_DATE_SHORTCODE;
     WPFunctions::set(Stub::make(new WPFunctions, [
@@ -54,7 +54,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals('success');
   }
 
-  function testDateShortcodeHandlerReturnsCurrentDateWhenDateIsMissingInQueueMeta() {
+  public function testDateShortcodeHandlerReturnsCurrentDateWhenDateIsMissingInQueueMeta() {
     $event = new FirstPurchase();
     $shortcode = $event::ORDER_DATE_SHORTCODE;
     $queue = SendingQueue::create(['task_id' => 1]);
@@ -66,7 +66,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals('success');
   }
 
-  function testDateShortcodeHandlerReturnsSystemFormattedDate() {
+  public function testDateShortcodeHandlerReturnsSystemFormattedDate() {
     $event = new FirstPurchase();
     $shortcode = $event::ORDER_DATE_SHORTCODE;
     $queue = SendingQueue::create(['task_id' => 1]);
@@ -77,7 +77,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals('success');
   }
 
-  function testOrderAmountShortcodeHandlerReturnsShortcodeWhenItCannotDetectProperShortcode() {
+  public function testOrderAmountShortcodeHandlerReturnsShortcodeWhenItCannotDetectProperShortcode() {
     $event = new FirstPurchase();
     $shortcode = 'wrong shortcode';
 
@@ -85,7 +85,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals($shortcode);
   }
 
-  function testOrderAmountShortcodeHandlerReturnsFormattedZeroValueWhenQueueIsMissing() {
+  public function testOrderAmountShortcodeHandlerReturnsFormattedZeroValueWhenQueueIsMissing() {
     $helper = Stub::make(WCHelper::class, [
       'wcPrice' => function($price) {
         return $price;
@@ -97,7 +97,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals(0);
   }
 
-  function testOrderAmountShortcodeHandlerReturnsFormattedZeroValueWhenOrderAmountIsMissingInQueueMeta() {
+  public function testOrderAmountShortcodeHandlerReturnsFormattedZeroValueWhenOrderAmountIsMissingInQueueMeta() {
     $helper = Stub::make(WCHelper::class, [
       'wcPrice' => function($price) {
         return $price;
@@ -110,7 +110,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals(0);
   }
 
-  function testOrderAmountShortcodeHandlerReturnsFormattedPrice() {
+  public function testOrderAmountShortcodeHandlerReturnsFormattedPrice() {
     $helper = Stub::make(WCHelper::class, [
       'wcPrice' => function($price) {
         return $price;
@@ -124,7 +124,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->equals(15);
   }
 
-  function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
+  public function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
     $helper = Stub::make(WCHelper::class, [
       'wcGetOrder' => false,
     ]);
@@ -133,7 +133,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItDoesNotScheduleEmailWhenCustomerEmailIsEmpty() {
+  public function testItDoesNotScheduleEmailWhenCustomerEmailIsEmpty() {
     $order_details = Stub::make(
       new OrderDetails(),
       [
@@ -149,7 +149,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItDoesNotScheduleEmailWhenItIsNotCustomersFirstPurchase() {
+  public function testItDoesNotScheduleEmailWhenItIsNotCustomersFirstPurchase() {
     $order_details = Stub::make(new OrderDetails(), ['get_billing_email' => 'test@example.com']);
     $helper = Stub::make(WCHelper::class, [
       'wcGetOrder' => $order_details,
@@ -161,7 +161,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItDoesNotScheduleEmailWhenCustomerIsNotAWCSegmentSubscriber() {
+  public function testItDoesNotScheduleEmailWhenCustomerIsNotAWCSegmentSubscriber() {
     $date_created = new \DateTime('2018-12-12');
     $order_details = Stub::make(
       new OrderDetails(),
@@ -192,17 +192,17 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItSchedulesEmailForProcessingOrder() {
+  public function testItSchedulesEmailForProcessingOrder() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_processing');
     $this->_runTestItSchedulesEmailForState('processing');
   }
 
-  function testItSchedulesEmailForCompletedOrder() {
+  public function testItSchedulesEmailForCompletedOrder() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_completed');
     $this->_runTestItSchedulesEmailForState('completed');
   }
 
-  function testItSchedulesEmailOnlyOnce() {
+  public function testItSchedulesEmailOnlyOnce() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_processing');
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_completed');
     $order_id = $this->_runTestItSchedulesEmailForState('processing');
@@ -212,7 +212,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     expect($tasks_count_after_status_change)->equals($tasks_count_before_status_change);
   }
 
-  function _runTestItSchedulesEmailForState($order_state) {
+  public function _runTestItSchedulesEmailForState($order_state) {
     $newsletter = Newsletter::createOrUpdate(
       [
         'subject' => 'WooCommerce',
@@ -287,7 +287,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     return $order_id;
   }
 
-  function _createNewsletterOption(array $options, $newsletter_id) {
+  public function _createNewsletterOption(array $options, $newsletter_id) {
     foreach ($options as $option => $value) {
       $newsletter_option_field = NewsletterOptionField::where('name', $option)
         ->where('newsletter_type', Newsletter::TYPE_AUTOMATIC)
@@ -320,7 +320,7 @@ class FirstPurchaseTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedInCategoryTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedInCategoryTest.php
index 5cc05612e3..21666d4a6f 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedInCategoryTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedInCategoryTest.php
@@ -26,7 +26,7 @@ class PurchasedInCategoryTest extends \MailPoetTest {
   /** @var PurchasedInCategory */
   private $event;
 
-  function _before() {
+  public function _before() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
@@ -40,13 +40,13 @@ class PurchasedInCategoryTest extends \MailPoetTest {
     $this->event = new PurchasedInCategory($this->woocommerce_helper);
   }
 
-  function testItGetsEventDetails() {
+  public function testItGetsEventDetails() {
     $result = $this->event->getEventDetails();
     expect($result)->notEmpty();
     expect($result['slug'])->equals(PurchasedInCategory::SLUG);
   }
 
-  function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
+  public function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
     $this->woocommerce_helper
       ->expects($this->once())
       ->method('wcGetOrder')
@@ -54,7 +54,7 @@ class PurchasedInCategoryTest extends \MailPoetTest {
     $this->event->scheduleEmail(1);
   }
 
-  function testItDoesNotScheduleEmailWhenNoSubscriber() {
+  public function testItDoesNotScheduleEmailWhenNoSubscriber() {
     $order = $this->getOrderMock();
     $this->woocommerce_helper
       ->expects($this->once())
@@ -67,7 +67,7 @@ class PurchasedInCategoryTest extends \MailPoetTest {
     $this->event->scheduleEmail(2);
   }
 
-  function testItSchedules() {
+  public function testItSchedules() {
     $newsletter = Newsletter::createOrUpdate(
       [
         'subject' => 'WooCommerce',
@@ -153,7 +153,7 @@ class PurchasedInCategoryTest extends \MailPoetTest {
     return $order_mock;
   }
 
-  function _createNewsletterOption(array $options, $newsletter_id) {
+  public function _createNewsletterOption(array $options, $newsletter_id) {
     foreach ($options as $option => $value) {
       $newsletter_option_field = NewsletterOptionField::where('name', $option)
         ->where('newsletter_type', Newsletter::TYPE_AUTOMATIC)
diff --git a/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedProductTest.php b/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedProductTest.php
index 47c841f841..e6d843c939 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedProductTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/Events/PurchasedProductTest.php
@@ -26,18 +26,18 @@ require_once __DIR__ . '/../WooCommerceStubs/ItemDetails.php';
 require_once __DIR__ . '/../WooCommerceStubs/OrderDetails.php';
 
 class PurchasedProductTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     WPFunctions::get()->removeAllFilters('woocommerce_payment_complete');
   }
 
-  function testItGetsEventDetails() {
+  public function testItGetsEventDetails() {
     $event = new PurchasedProduct();
     $result = $event->getEventDetails();
     expect($result)->notEmpty();
     expect($result['slug'])->equals(PurchasedProduct::SLUG);
   }
 
-  function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
+  public function testItDoesNotScheduleEmailWhenOrderDetailsAreNotAvailable() {
     $helper = Stub::make(WCHelper::class, [
       'wcGetOrder' => false,
     ]);
@@ -46,7 +46,7 @@ class PurchasedProductTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItDoesNotScheduleEmailWhenCustomerEmailIsEmpty() {
+  public function testItDoesNotScheduleEmailWhenCustomerEmailIsEmpty() {
     $order_details = Stub::make(
       new OrderDetails(),
       [
@@ -63,7 +63,7 @@ class PurchasedProductTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function testItDoesNotScheduleEmailWhenCustomerIsNotAWCSegmentSubscriber() {
+  public function testItDoesNotScheduleEmailWhenCustomerIsNotAWCSegmentSubscriber() {
     $order_details = Stub::make(
       new OrderDetails(),
       [
@@ -91,7 +91,7 @@ class PurchasedProductTest extends \MailPoetTest {
   }
 
 
-  function testItDoesNotScheduleEmailWhenPurchasedProductDoesNotMatchConfiguredProductIds() {
+  public function testItDoesNotScheduleEmailWhenPurchasedProductDoesNotMatchConfiguredProductIds() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_completed');
     $newsletter = Newsletter::createOrUpdate(
       [
@@ -162,18 +162,18 @@ class PurchasedProductTest extends \MailPoetTest {
     expect($scheduled_task)->isEmpty();
   }
 
-  function testItSchedulesEmailForProcessingOrder() {
+  public function testItSchedulesEmailForProcessingOrder() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_processing');
     $this->_runTestItSchedulesEmailForState('processing');
   }
 
-  function testItSchedulesEmailForCompletedOrder() {
+  public function testItSchedulesEmailForCompletedOrder() {
     WPFunctions::get()->removeAllFilters('woocommerce_order_status_completed');
     $this->_runTestItSchedulesEmailForState('completed');
   }
 
 
-  function _runTestItSchedulesEmailForState($state) {
+  public function _runTestItSchedulesEmailForState($state) {
     $newsletter = Newsletter::createOrUpdate(
       [
         'subject' => 'WooCommerce',
@@ -256,7 +256,7 @@ class PurchasedProductTest extends \MailPoetTest {
     return $order_id;
   }
 
-  function _createNewsletterOption(array $options, $newsletter_id) {
+  public function _createNewsletterOption(array $options, $newsletter_id) {
     foreach ($options as $option => $value) {
       $newsletter_option_field = NewsletterOptionField::where('name', $option)
         ->where('newsletter_type', Newsletter::TYPE_AUTOMATIC)
@@ -289,7 +289,7 @@ class PurchasedProductTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
diff --git a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/ItemDetails.php b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/ItemDetails.php
index ee01d8477e..9abb5e344f 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/ItemDetails.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/ItemDetails.php
@@ -4,6 +4,6 @@ namespace MailPoet\AutomaticEmails\WooCommerce\WooCommerceStubs;
 
 // phpcs:disable PSR1.Methods.CamelCapsMethodName
 class ItemDetails {
-  function get_product_id() { 
+  public function get_product_id() {
   }
 }
diff --git a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/OrderDetails.php b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/OrderDetails.php
index 76de156d9e..8de6a9ed18 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/OrderDetails.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceStubs/OrderDetails.php
@@ -10,28 +10,28 @@ class OrderDetails
   public $total;
   public $order_id;
 
-  function __construct($order_id = null) {
+  public function __construct($order_id = null) {
     $this->order_id = $order_id;
   }
 
-  function get_customer_id() {
+  public function get_customer_id() {
   }
 
-  function get_billing_email() {
+  public function get_billing_email() {
   }
 
-  function get_date_created() {
+  public function get_date_created() {
   }
 
-  function get_id() {
+  public function get_id() {
     return $this->order_id;
   }
 
-  function get_total() {
+  public function get_total() {
     return $this->total;
   }
 
-  function get_items() {
+  public function get_items() {
     return new ItemDetails();
   }
 }
diff --git a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceTest.php b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceTest.php
index 58e4008d62..6ca9fb38e6 100644
--- a/tests/integration/AutomaticEmails/WooCommerce/WooCommerceTest.php
+++ b/tests/integration/AutomaticEmails/WooCommerce/WooCommerceTest.php
@@ -11,7 +11,7 @@ use MailPoet\AutomaticEmails\WooCommerce\Events\PurchasedProduct;
 use MailPoet\WP\Functions as WPFunctions;
 
 class WooCommerceTest extends \MailPoetTest {
-  function testItRegistersAbandonedCartEvent() {
+  public function testItRegistersAbandonedCartEvent() {
     $WC = Stub::make(new WooCommerce(), ['isWoocommerceEnabled' => true]);
     $WC->__construct();
     $WC->init();
@@ -22,7 +22,7 @@ class WooCommerceTest extends \MailPoetTest {
     expect($result)->notEmpty();
   }
 
-  function testItRegistersFirstPuchaseEvent() {
+  public function testItRegistersFirstPuchaseEvent() {
     $WC = Stub::make(new WooCommerce(), ['isWoocommerceEnabled' => true]);
     $WC->__construct();
     $WC->init();
@@ -38,7 +38,7 @@ class WooCommerceTest extends \MailPoetTest {
     expect(has_filter('woocommerce_order_status_processing'))->true();
   }
 
-  function testItRegistersPurchasedInCategoryEvent() {
+  public function testItRegistersPurchasedInCategoryEvent() {
     $WC = Stub::make(new WooCommerce(), ['isWoocommerceEnabled' => true]);
     $WC->__construct();
     $WC->init();
@@ -49,7 +49,7 @@ class WooCommerceTest extends \MailPoetTest {
     expect($result)->notEmpty();
   }
 
-  function testItRegistersPurchasedProductEvent() {
+  public function testItRegistersPurchasedProductEvent() {
     $WC = Stub::make(new WooCommerce(), ['isWoocommerceEnabled' => true]);
     $WC->__construct();
     $WC->init();
@@ -65,7 +65,7 @@ class WooCommerceTest extends \MailPoetTest {
     expect(has_filter('woocommerce_product_purchased_get_products'))->true();
   }
 
-  function testItReplacesEventActionButtonWithLinkToWCPluginRepoWhenWCIsDisabled() {
+  public function testItReplacesEventActionButtonWithLinkToWCPluginRepoWhenWCIsDisabled() {
     $WC = Stub::make(new WooCommerce(), ['isWoocommerceEnabled' => false]);
     $WC->__construct();
     $WC->init();
@@ -87,7 +87,7 @@ class WooCommerceTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     $wp = new WPFunctions;
     $wp->removeAllFilters('mailpoet_newsletter_shortcode');
     $wp->removeAllFilters('woocommerce_payment_complete');
diff --git a/tests/integration/Config/AccessControlTest.php b/tests/integration/Config/AccessControlTest.php
index c5a602b525..7442e1ac6c 100644
--- a/tests/integration/Config/AccessControlTest.php
+++ b/tests/integration/Config/AccessControlTest.php
@@ -11,12 +11,12 @@ class AccessControlTest extends \MailPoetTest {
   /** @var AccessControl */
   private $access_control;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->access_control = new AccessControl;
   }
 
-  function testItAllowsSettingCustomPermissions() {
+  public function testItAllowsSettingCustomPermissions() {
     $wp = new WPFunctions;
     $wp->addFilter(
       'mailpoet_permission_access_plugin_admin',
@@ -88,13 +88,13 @@ class AccessControlTest extends \MailPoetTest {
     );
   }
 
-  function testItGetsPermissionLabels() {
+  public function testItGetsPermissionLabels() {
     $permissions = $this->access_control->getDefaultPermissions();
     $labels = $this->access_control->getPermissionLabels();
     expect(count($permissions))->equals(count($labels));
   }
 
-  function testItValidatesIfUserHasCapability() {
+  public function testItValidatesIfUserHasCapability() {
     $capability = 'some_capability';
     $access_control = new AccessControl();
     WPFunctions::set(Stub::make(new WPFunctions, [
@@ -104,7 +104,7 @@ class AccessControlTest extends \MailPoetTest {
     expect($access_control->validatePermission($capability))->true();
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/integration/Config/CapabilitiesTest.php b/tests/integration/Config/CapabilitiesTest.php
index 7ff84e0dea..aa601b8b3d 100644
--- a/tests/integration/Config/CapabilitiesTest.php
+++ b/tests/integration/Config/CapabilitiesTest.php
@@ -18,14 +18,14 @@ class CapabilitiesTest extends \MailPoetTest {
   /** @var Capabilities */
   private $caps;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $renderer = new Renderer();
     $this->caps = new Capabilities($renderer);
     $this->access_control = new AccessControl();
   }
 
-  function testItInitializes() {
+  public function testItInitializes() {
     $caps = Stub::makeEmptyExcept(
       $this->caps,
       'init',
@@ -35,7 +35,7 @@ class CapabilitiesTest extends \MailPoetTest {
     $caps->init();
   }
 
-  function testItSetsUpWPCapabilities() {
+  public function testItSetsUpWPCapabilities() {
     $permissions = $this->access_control->getDefaultPermissions();
     $this->caps->setupWPCapabilities();
     $checked = false;
@@ -48,7 +48,7 @@ class CapabilitiesTest extends \MailPoetTest {
     expect($checked)->true();
   }
 
-  function testItRemovesWPCapabilities() {
+  public function testItRemovesWPCapabilities() {
     $permissions = $this->access_control->getDefaultPermissions();
     $this->caps->removeWPCapabilities();
     $checked = false;
@@ -63,7 +63,7 @@ class CapabilitiesTest extends \MailPoetTest {
     $this->caps->setupWPCapabilities();
   }
 
-  function testItDoesNotSetupCapabilitiesForNonexistentRoles() {
+  public function testItDoesNotSetupCapabilitiesForNonexistentRoles() {
     $this->caps->removeWPCapabilities();
 
     $filter = function() {
@@ -90,7 +90,7 @@ class CapabilitiesTest extends \MailPoetTest {
     expect($editor_role->has_cap(AccessControl::PERMISSION_MANAGE_EMAILS))->true();
   }
 
-  function testItSetsUpMembersCapabilities() {
+  public function testItSetsUpMembersCapabilities() {
     $wp = Stub::make(new WPFunctions, [
       'addAction' => asCallable([WPHooksHelper::class, 'addAction']),
     ]);
@@ -107,7 +107,7 @@ class CapabilitiesTest extends \MailPoetTest {
     expect(is_callable(WPHooksHelper::getActionAdded($hook_name)[0]))->true();
   }
 
-  function testItRegistersMembersCapabilities() {
+  public function testItRegistersMembersCapabilities() {
     $permissions = $this->access_control->getPermissionLabels();
     $permission_count = count($permissions);
     if (function_exists('members_register_cap')) { // Members plugin active
diff --git a/tests/integration/Config/DatabaseTest.php b/tests/integration/Config/DatabaseTest.php
index 9c1bac4a70..e71d18e62c 100644
--- a/tests/integration/Config/DatabaseTest.php
+++ b/tests/integration/Config/DatabaseTest.php
@@ -9,25 +9,25 @@ use MailPoetVendor\Idiorm\ORM;
 class DatabaseTest extends \MailPoetTest {
   public $database;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->database = new Database();
   }
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::set_db(null);
   }
 
-  function testItDefinesTables() {
+  public function testItDefinesTables() {
     expect(defined('MP_SETTINGS_TABLE'))->true();
   }
 
-  function testItConfiguresLogging() {
+  public function testItConfiguresLogging() {
     expect(ORM::get_config('logging'))->equals(WP_DEBUG);
   }
 
-  function testItSetsDBDriverOptions() {
+  public function testItSetsDBDriverOptions() {
     $this->database->init($this->connection->getWrappedConnection());
     $result = ORM::for_table("")
       ->raw_query(
diff --git a/tests/integration/Config/EnvTest.php b/tests/integration/Config/EnvTest.php
index 288c2a026c..d6c139746e 100644
--- a/tests/integration/Config/EnvTest.php
+++ b/tests/integration/Config/EnvTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Config;
 use MailPoet\Config\Env;
 
 class EnvTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // Back up original environment values
     $this->file = Env::$file;
@@ -13,17 +13,17 @@ class EnvTest extends \MailPoetTest {
     Env::init('file', '1.0.0', 'localhost:3306', DB_USER, DB_PASSWORD, DB_NAME);
   }
 
-  function testItCanReturnPluginPrefix() {
+  public function testItCanReturnPluginPrefix() {
     expect(Env::$plugin_prefix)->equals('mailpoet_');
   }
 
-  function testItCanReturnDbPrefix() {
+  public function testItCanReturnDbPrefix() {
     global $wpdb;
     $db_prefix = $wpdb->prefix . 'mailpoet_';
     expect(Env::$db_prefix)->equals($db_prefix);
   }
 
-  function testItProcessDBHost() {
+  public function testItProcessDBHost() {
     Env::init('file', '1.0.0', 'localhost', 'db_user', 'pass123', 'db_name');
     expect(Env::$db_host)->equals('localhost');
     expect(Env::$db_port)->equals('3306');
@@ -33,13 +33,13 @@ class EnvTest extends \MailPoetTest {
     expect(Env::$db_port)->equals('3307');
   }
 
-  function testItProcessDBHostWithSocket() {
+  public function testItProcessDBHostWithSocket() {
     Env::init('file', '1.0.0', 'localhost:/var/lib/mysql/mysql55.sock', 'db_user', 'pass123', 'db_name');
     expect(Env::$db_host)->equals('localhost');
     expect(Env::$db_socket)->equals('/var/lib/mysql/mysql55.sock');
   }
 
-  function testItProcessDBHostWithIpV6Address() {
+  public function testItProcessDBHostWithIpV6Address() {
     Env::init('file', '1.0.0', '::1', 'db_user', 'pass123', 'db_name');
     expect(Env::$db_host)->equals('::1');
     expect(Env::$db_socket)->equals(null);
@@ -49,43 +49,43 @@ class EnvTest extends \MailPoetTest {
     expect(Env::$db_socket)->equals(null);
   }
 
-  function testItCanReturnDbName() {
+  public function testItCanReturnDbName() {
     expect(Env::$db_name)->equals(DB_NAME);
   }
 
-  function testItCanReturnDbUser() {
+  public function testItCanReturnDbUser() {
     expect(Env::$db_username)->equals(DB_USER);
   }
 
-  function testItCanReturnDbPassword() {
+  public function testItCanReturnDbPassword() {
     expect(Env::$db_password)->equals(DB_PASSWORD);
   }
 
-  function testItCanReturnDbCharset() {
+  public function testItCanReturnDbCharset() {
     global $wpdb;
     $charset = $wpdb->charset;
     expect(Env::$db_charset)->equals($charset);
   }
 
-  function testItCanReturnDbCollation() {
+  public function testItCanReturnDbCollation() {
     global $wpdb;
     $collation = $wpdb->collate;
     expect(Env::$db_collation)->equals($collation);
   }
 
-  function testItCanReturnDbCharsetCollate() {
+  public function testItCanReturnDbCharsetCollate() {
     global $wpdb;
     $charset_collate = $wpdb->get_charset_collate();
     expect(Env::$db_charset_collate)->equals($charset_collate);
   }
 
-  function testItCanGetDbTimezoneOffset() {
+  public function testItCanGetDbTimezoneOffset() {
     expect(Env::getDbTimezoneOffset('+1.5'))->equals("+01:30");
     expect(Env::getDbTimezoneOffset('+11'))->equals("+11:00");
     expect(Env::getDbTimezoneOffset('-5.5'))->equals("-05:30");
   }
 
-  function _after() {
+  public function _after() {
     // Restore the original environment
     Env::init($this->file, $this->version, DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
   }
diff --git a/tests/integration/Config/HooksTest.php b/tests/integration/Config/HooksTest.php
index a55d54843f..b9d371f9b6 100644
--- a/tests/integration/Config/HooksTest.php
+++ b/tests/integration/Config/HooksTest.php
@@ -6,7 +6,7 @@ use MailPoet\Config\Hooks;
 use MailPoet\DI\ContainerWrapper;
 
 class HooksTest extends \MailPoetTest {
-  function testItHooksSchedulerToMultiplePostTypes() {
+  public function testItHooksSchedulerToMultiplePostTypes() {
     $hooks = ContainerWrapper::getInstance()->get(Hooks::class);
     $hooks->setupPostNotifications();
     expect(has_filter('transition_post_status'))->notEmpty();
diff --git a/tests/integration/Config/InitializerTest.php b/tests/integration/Config/InitializerTest.php
index 758b97e6f0..b63f059e5e 100644
--- a/tests/integration/Config/InitializerTest.php
+++ b/tests/integration/Config/InitializerTest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Test\Config;
 
 class InitializerTest extends \MailPoetTest {
-  function testItConfiguresHooks() {
+  public function testItConfiguresHooks() {
     global $wp_filter;
     $is_hooked = false;
     // mailpoet should hook to 'wp_loaded' with priority of 10
diff --git a/tests/integration/Config/InstallerTest.php b/tests/integration/Config/InstallerTest.php
index c42ab026ce..478482fa73 100644
--- a/tests/integration/Config/InstallerTest.php
+++ b/tests/integration/Config/InstallerTest.php
@@ -8,7 +8,7 @@ use MailPoet\Config\Env;
 use MailPoet\Config\Installer;
 
 class InstallerTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->slug = 'some-plugin';
 
@@ -17,7 +17,7 @@ class InstallerTest extends \MailPoetTest {
     );
   }
 
-  function testItInitializes() {
+  public function testItInitializes() {
     $installer = Stub::make(
       $this->installer,
       [
@@ -29,7 +29,7 @@ class InstallerTest extends \MailPoetTest {
     apply_filters('plugins_api', null, null, null);
   }
 
-  function testItGetsPluginInformation() {
+  public function testItGetsPluginInformation() {
     $args = new \StdClass;
     $args->slug = $this->slug;
     $installer = Stub::construct(
@@ -66,7 +66,7 @@ class InstallerTest extends \MailPoetTest {
     expect($result->package)->notEmpty();
   }
 
-  function testItIgnoresNonMatchingRequestsWhenGettingPluginInformation() {
+  public function testItIgnoresNonMatchingRequestsWhenGettingPluginInformation() {
     $data = new \StdClass;
     $data->some_property = '123';
     $result = $this->installer->getPluginInformation($data, 'some_action', null);
@@ -77,7 +77,7 @@ class InstallerTest extends \MailPoetTest {
     expect($result)->equals($data);
   }
 
-  function testItGetsPremiumStatus() {
+  public function testItGetsPremiumStatus() {
     $status = Installer::getPremiumStatus();
     expect(isset($status['premium_plugin_active']))->true();
     expect(isset($status['premium_plugin_installed']))->true();
@@ -85,17 +85,17 @@ class InstallerTest extends \MailPoetTest {
     expect(isset($status['premium_activate_url']))->true();
   }
 
-  function testItChecksIfAPluginIsInstalled() {
+  public function testItChecksIfAPluginIsInstalled() {
     expect(Installer::isPluginInstalled(Env::$plugin_name))->true();
     expect(Installer::isPluginInstalled('some-non-existent-plugin-123'))->false();
   }
 
-  function testItGetsPluginInstallUrl() {
+  public function testItGetsPluginInstallUrl() {
     expect(Installer::getPluginInstallationUrl(Env::$plugin_name))
       ->startsWith(home_url() . '/wp-admin/update.php?action=install-plugin&plugin=mailpoet&_wpnonce=');
   }
 
-  function testItGetsPluginActivateUrl() {
+  public function testItGetsPluginActivateUrl() {
     expect(Installer::getPluginActivationUrl(Env::$plugin_name))
       ->startsWith(home_url() . '/wp-admin/plugins.php?action=activate&plugin=mailpoet/mailpoet.php&_wpnonce=');
   }
diff --git a/tests/integration/Config/MenuTest.php b/tests/integration/Config/MenuTest.php
index c980488cce..5260c6c99c 100644
--- a/tests/integration/Config/MenuTest.php
+++ b/tests/integration/Config/MenuTest.php
@@ -13,14 +13,14 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoetVendor\Doctrine\ORM\EntityManager;
 
 class MenuTest extends \MailPoetTest {
-  function testItReturnsTrueIfCurrentPageBelongsToMailpoet() {
+  public function testItReturnsTrueIfCurrentPageBelongsToMailpoet() {
     $result = Menu::isOnMailPoetAdminPage(null, 'somepage');
     expect($result)->false();
     $result = Menu::isOnMailPoetAdminPage(null, 'mailpoet-newsletters');
     expect($result)->true();
   }
 
-  function testItRespectsExclusionsWhenCheckingMPPages() {
+  public function testItRespectsExclusionsWhenCheckingMPPages() {
     $exclude = ['mailpoet-welcome'];
     $result = Menu::isOnMailPoetAdminPage($exclude, 'mailpoet-welcome');
     expect($result)->false();
@@ -28,7 +28,7 @@ class MenuTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItWorksWithRequestDataWhenCheckingMPPages() {
+  public function testItWorksWithRequestDataWhenCheckingMPPages() {
     $_REQUEST['page'] = 'mailpoet-newsletters';
     $result = Menu::isOnMailPoetAdminPage();
     expect($result)->true();
@@ -42,7 +42,7 @@ class MenuTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItChecksMailpoetAPIKey() {
+  public function testItChecksMailpoetAPIKey() {
     $menu = $this->getMenu();
 
     $_REQUEST['page'] = 'mailpoet-newsletters';
@@ -63,7 +63,7 @@ class MenuTest extends \MailPoetTest {
     expect($menu->mp_api_key_valid)->false();
   }
 
-  function testItChecksPremiumKey() {
+  public function testItChecksPremiumKey() {
     $menu = $this->getMenu();
 
     $_REQUEST['page'] = 'mailpoet-newsletters';
diff --git a/tests/integration/Config/MigratorTest.php b/tests/integration/Config/MigratorTest.php
index 563f3a0f75..697433186d 100644
--- a/tests/integration/Config/MigratorTest.php
+++ b/tests/integration/Config/MigratorTest.php
@@ -5,18 +5,18 @@ namespace MailPoet\Test\Config;
 use MailPoet\Config\Migrator;
 
 class MigratorTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->migrator = new Migrator();
   }
 
-  function testItCanGenerateTheSubscribersSql() {
+  public function testItCanGenerateTheSubscribersSql() {
     $subscriber_sql = $this->migrator->subscribers();
     $expected_table = $this->migrator->prefix . 'subscribers';
     expect($subscriber_sql)->contains($expected_table);
   }
 
-  function testItDoesNotMigrateWhenDatabaseIsUpToDate() {
+  public function testItDoesNotMigrateWhenDatabaseIsUpToDate() {
     $changes = $this->migrator->up();
     $this->assertEmpty(
       $changes,
@@ -24,6 +24,6 @@ class MigratorTest extends \MailPoetTest {
     );
   }
 
-  function _after() {
+  public function _after() {
   }
 }
diff --git a/tests/integration/Config/RendererTest.php b/tests/integration/Config/RendererTest.php
index 45462cfa88..73ff9e4309 100644
--- a/tests/integration/Config/RendererTest.php
+++ b/tests/integration/Config/RendererTest.php
@@ -9,12 +9,12 @@ use MailPoet\Config\Renderer;
 use MailPoetVendor\Twig_Environment;
 
 class RendererTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->renderer = new Renderer($caching = false, $debugging = false);
   }
 
-  function testItUsesCorrectAssetsManifestFilenames() {
+  public function testItUsesCorrectAssetsManifestFilenames() {
     $renderer = Stub::make(new Renderer(),
       ['getAssetManifest' => function($manifest) {
         return $manifest;
@@ -25,7 +25,7 @@ class RendererTest extends \MailPoetTest {
     expect($renderer->assets_manifest_css)->equals(Env::$assets_path . '/dist/css/manifest.json');
   }
 
-  function testItGetsAssetManifest() {
+  public function testItGetsAssetManifest() {
     $assets_manifest_js = [
       'script1.js' => 'script1.hash.js',
       'script2.js' => 'script2.hash.js',
@@ -41,11 +41,11 @@ class RendererTest extends \MailPoetTest {
     expect($this->renderer->getAssetManifest(Env::$temp_path . '/css.json'))->equals($assets_manifest_css);
   }
 
-  function testItReturnsFalseAssetManifestDoesNotExist() {
+  public function testItReturnsFalseAssetManifestDoesNotExist() {
     expect($this->renderer->getAssetManifest(Env::$temp_path . '/js.json'))->false();
   }
 
-  function testItCanGetCssAsset() {
+  public function testItCanGetCssAsset() {
     $assets_manifest_css = [
       'style1.css' => 'style1.hash.css',
       'style2.css' => 'style2.hash.css',
@@ -56,7 +56,7 @@ class RendererTest extends \MailPoetTest {
     expect($renderer->getCssAsset('style2.css'))->equals('style2.hash.css');
   }
 
-  function testItCanGetJsAsset() {
+  public function testItCanGetJsAsset() {
     $assets_manifest_js = [
       'script1.js' => 'script1.hash.js',
       'script2.js' => 'script2.hash.js',
@@ -67,12 +67,12 @@ class RendererTest extends \MailPoetTest {
     expect($renderer->getJsAsset('script2.js'))->equals('script2.hash.js');
   }
 
-  function testItWillNotEnableCacheWhenWpDebugIsOn() {
+  public function testItWillNotEnableCacheWhenWpDebugIsOn() {
     $result = $this->renderer->detectCache();
     expect($result)->equals(false);
   }
 
-  function testItDelegatesRenderingToTwig() {
+  public function testItDelegatesRenderingToTwig() {
     $renderer = Stub::construct(
       $this->renderer,
       [],
@@ -91,7 +91,7 @@ class RendererTest extends \MailPoetTest {
     expect($renderer->render('non-existing-template.html', ['somekey' => 'someval']))->equals('test render');
   }
 
-  function testItRethrowsTwigCacheExceptions() {
+  public function testItRethrowsTwigCacheExceptions() {
     $exception_message = 'this is a test error';
     $renderer = Stub::construct(
       $this->renderer,
@@ -117,11 +117,11 @@ class RendererTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     $this->_removeAssetsManifests();
   }
 
-  function _removeAssetsManifests() {
+  public function _removeAssetsManifests() {
     if (is_readable(Env::$temp_path . '/js.json')) unlink(Env::$temp_path . '/js.json');
     if (is_readable(Env::$temp_path . '/css.json')) unlink(Env::$temp_path . '/css.json');
   }
diff --git a/tests/integration/Config/ServicesCheckerTest.php b/tests/integration/Config/ServicesCheckerTest.php
index 51e8960fc4..145619f836 100644
--- a/tests/integration/Config/ServicesCheckerTest.php
+++ b/tests/integration/Config/ServicesCheckerTest.php
@@ -15,7 +15,7 @@ class ServicesCheckerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->setMailPoetSendingMethod();
@@ -23,25 +23,25 @@ class ServicesCheckerTest extends \MailPoetTest {
     $this->services_checker = new ServicesChecker();
   }
 
-  function testItDoesNotCheckMSSKeyIfMPSendingServiceIsDisabled() {
+  public function testItDoesNotCheckMSSKeyIfMPSendingServiceIsDisabled() {
     $this->disableMailPoetSendingMethod();
     $result = $this->services_checker->isMailPoetAPIKeyValid();
     expect($result)->null();
   }
 
-  function testItForciblyChecksMSSKeyIfMPSendingServiceIsDisabled() {
+  public function testItForciblyChecksMSSKeyIfMPSendingServiceIsDisabled() {
     $this->disableMailPoetSendingMethod();
     $result = $this->services_checker->isMailPoetAPIKeyValid(false, true);
     expect($result)->false();
   }
 
-  function testItReturnsFalseIfMSSKeyIsNotSpecified() {
+  public function testItReturnsFalseIfMSSKeyIsNotSpecified() {
     $this->settings->set(Bridge::API_KEY_SETTING_NAME, '');
     $result = $this->services_checker->isMailPoetAPIKeyValid();
     expect($result)->false();
   }
 
-  function testItReturnsTrueIfMSSKeyIsValid() {
+  public function testItReturnsTrueIfMSSKeyIsValid() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_VALID]
@@ -50,7 +50,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItReturnsFalseIfMSSKeyIsInvalid() {
+  public function testItReturnsFalseIfMSSKeyIsInvalid() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_INVALID]
@@ -59,7 +59,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsTrueIfMSSKeyIsExpiring() {
+  public function testItReturnsTrueIfMSSKeyIsExpiring() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       [
@@ -71,7 +71,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItReturnsFalseIfMSSKeyStateIsUnexpected() {
+  public function testItReturnsFalseIfMSSKeyStateIsUnexpected() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       [
@@ -82,7 +82,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsFalseIfMSSKeyStateIsEmpty() {
+  public function testItReturnsFalseIfMSSKeyStateIsEmpty() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       [
@@ -93,13 +93,13 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsFalseIfPremiumKeyIsNotSpecified() {
+  public function testItReturnsFalseIfPremiumKeyIsNotSpecified() {
     $this->clearPremiumKey();
     $result = $this->services_checker->isPremiumKeyValid();
     expect($result)->false();
   }
 
-  function testItReturnsTrueIfPremiumKeyIsValid() {
+  public function testItReturnsTrueIfPremiumKeyIsValid() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_VALID]
@@ -108,7 +108,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItReturnsFalseIfPremiumKeyIsInvalid() {
+  public function testItReturnsFalseIfPremiumKeyIsInvalid() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_INVALID]
@@ -117,7 +117,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsFalseIfPremiumKeyIsAlreadyUsed() {
+  public function testItReturnsFalseIfPremiumKeyIsAlreadyUsed() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_ALREADY_USED]
@@ -126,7 +126,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsTrueIfPremiumKeyIsExpiring() {
+  public function testItReturnsTrueIfPremiumKeyIsExpiring() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       [
@@ -138,7 +138,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItReturnsFalseIfPremiumKeyStateIsUnexpected() {
+  public function testItReturnsFalseIfPremiumKeyStateIsUnexpected() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       [
@@ -149,7 +149,7 @@ class ServicesCheckerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReturnsFalseIfPremiumKeyStateIsEmpty() {
+  public function testItReturnsFalseIfPremiumKeyStateIsEmpty() {
     $this->settings->set(
       Bridge::PREMIUM_KEY_STATE_SETTING_NAME,
       [
diff --git a/tests/integration/Config/ShortcodesTest.php b/tests/integration/Config/ShortcodesTest.php
index 51a8109581..aef59c7240 100644
--- a/tests/integration/Config/ShortcodesTest.php
+++ b/tests/integration/Config/ShortcodesTest.php
@@ -17,7 +17,7 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoetVendor\Idiorm\ORM;
 
 class ShortcodesTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_STANDARD;
@@ -29,7 +29,7 @@ class ShortcodesTest extends \MailPoetTest {
     $this->queue = $queue->save();
   }
 
-  function testItGetsArchives() {
+  public function testItGetsArchives() {
     $shortcodes = ContainerWrapper::getInstance()->get(Shortcodes::class);
     WordPress::interceptFunction('apply_filters', function() use($shortcodes) {
       $args = func_get_args();
@@ -59,7 +59,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($request_data['newsletter_hash'])->equals($this->newsletter->hash);
   }
 
-  function testItDisplaysManageSubscriptionFormForLoggedinExistingUsers() {
+  public function testItDisplaysManageSubscriptionFormForLoggedinExistingUsers() {
     $wp_user = wp_set_current_user(1);
     expect((new WPFunctions)->isUserLoggedIn())->true();
     $subscriber = Subscriber::create();
@@ -75,7 +75,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains($subscriber->email);
   }
 
-  function testItDoesNotDisplayManageSubscriptionFormForLoggedinNonexistentSubscribers() {
+  public function testItDoesNotDisplayManageSubscriptionFormForLoggedinNonexistentSubscribers() {
     $wp_user = wp_set_current_user(1);
     expect((new WPFunctions)->isUserLoggedIn())->true();
     expect(Subscriber::findOne($wp_user->data->user_email))->false();
@@ -86,7 +86,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains('Subscription management form is only available to mailing lists subscribers.');
   }
 
-  function testItDoesNotDisplayManageSubscriptionFormForLoggedOutUsers() {
+  public function testItDoesNotDisplayManageSubscriptionFormForLoggedOutUsers() {
     wp_set_current_user(0);
     expect((new WPFunctions)->isUserLoggedIn())->false();
 
@@ -96,7 +96,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains('Subscription management form is only available to mailing lists subscribers.');
   }
 
-  function testItDisplaysLinkToManageSubscriptionPageForLoggedinExistingUsers() {
+  public function testItDisplaysLinkToManageSubscriptionPageForLoggedinExistingUsers() {
     $wp_user = wp_set_current_user(1);
     expect((new WPFunctions)->isUserLoggedIn())->true();
     $subscriber = Subscriber::create();
@@ -111,7 +111,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains('Manage your subscription');
   }
 
-  function testItDoesNotDisplayLinkToManageSubscriptionPageForLoggedinNonexistentSubscribers() {
+  public function testItDoesNotDisplayLinkToManageSubscriptionPageForLoggedinNonexistentSubscribers() {
     $wp_user = wp_set_current_user(1);
     expect((new WPFunctions)->isUserLoggedIn())->true();
     expect(Subscriber::findOne($wp_user->data->user_email))->false();
@@ -122,7 +122,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains('Link to subscription management page is only available to mailing lists subscribers.');
   }
 
-  function testItDoesNotDisplayManageSubscriptionPageForLoggedOutUsers() {
+  public function testItDoesNotDisplayManageSubscriptionPageForLoggedOutUsers() {
     wp_set_current_user(0);
     expect((new WPFunctions)->isUserLoggedIn())->false();
 
@@ -132,7 +132,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->contains('Link to subscription management page is only available to mailing lists subscribers.');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
diff --git a/tests/integration/Config/UpdaterTest.php b/tests/integration/Config/UpdaterTest.php
index ec9614912c..a263cb14d8 100644
--- a/tests/integration/Config/UpdaterTest.php
+++ b/tests/integration/Config/UpdaterTest.php
@@ -7,7 +7,7 @@ use Codeception\Stub\Expected;
 use MailPoet\Config\Updater;
 
 class UpdaterTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->plugin_name = 'some-plugin/some-plugin.php';
     $this->slug = 'some-plugin';
@@ -20,7 +20,7 @@ class UpdaterTest extends \MailPoetTest {
     );
   }
 
-  function testItInitializes() {
+  public function testItInitializes() {
     $updater = Stub::make(
       $this->updater,
       [
@@ -32,7 +32,7 @@ class UpdaterTest extends \MailPoetTest {
     apply_filters('pre_set_site_transient_update_plugins', null);
   }
 
-  function testItChecksForUpdates() {
+  public function testItChecksForUpdates() {
     $update_transient = new \StdClass;
     $update_transient->last_checked = time();
     $updater = Stub::construct(
@@ -69,7 +69,7 @@ class UpdaterTest extends \MailPoetTest {
     expect($result->response[$this->plugin_name]->package)->notEmpty();
   }
 
-  function testItReturnsObjectIfPassedNonObjectWhenCheckingForUpdates() {
+  public function testItReturnsObjectIfPassedNonObjectWhenCheckingForUpdates() {
     $result = $this->updater->checkForUpdate(null);
     expect($result instanceof \StdClass)->true();
   }
diff --git a/tests/integration/Cron/CronHelperTest.php b/tests/integration/Cron/CronHelperTest.php
index 5a335f69f5..c8e097a3d2 100644
--- a/tests/integration/Cron/CronHelperTest.php
+++ b/tests/integration/Cron/CronHelperTest.php
@@ -17,7 +17,7 @@ class CronHelperTest extends \MailPoetTest {
   /** @var CronHelper */
   private $cron_helper;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->settings->set('db_version', MAILPOET_VERSION);
@@ -32,13 +32,13 @@ class CronHelperTest extends \MailPoetTest {
     $this->cron_helper = new CronHelper($this->settings, new WPFunctions);
   }
 
-  function testItDefinesConstants() {
+  public function testItDefinesConstants() {
     expect(CronHelper::DAEMON_EXECUTION_LIMIT)->equals(20);
     expect(CronHelper::DAEMON_REQUEST_TIMEOUT)->equals(5);
     expect(CronHelper::DAEMON_SETTING)->equals('cron_daemon');
   }
 
-  function testItCreatesDaemon() {
+  public function testItCreatesDaemon() {
     $token = 'create_token';
     $time = time();
     $this->cron_helper->createDaemon($token);
@@ -57,7 +57,7 @@ class CronHelperTest extends \MailPoetTest {
     );
   }
 
-  function testItRestartsDaemon() {
+  public function testItRestartsDaemon() {
     $token = 'restart_token';
     $time = time();
     $this->cron_helper->restartDaemon($token);
@@ -76,7 +76,7 @@ class CronHelperTest extends \MailPoetTest {
     );
   }
 
-  function testItLoadsDaemon() {
+  public function testItLoadsDaemon() {
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
@@ -85,7 +85,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($this->cron_helper->getDaemon())->equals($daemon);
   }
 
-  function testItSavesDaemon() {
+  public function testItSavesDaemon() {
     // when saving daemon, 'updated_at' value should change
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
@@ -98,7 +98,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($this->cron_helper->getDaemon())->equals($daemon);
   }
 
-  function testItUpdatesDaemonAccessedAt() {
+  public function testItUpdatesDaemonAccessedAt() {
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
@@ -115,7 +115,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($updated_daemon['run_accessed_at'])->lessThan($time + 2);
   }
 
-  function testItThrowsAnExceptionIfAccessingNonExistingDaemon() {
+  public function testItThrowsAnExceptionIfAccessingNonExistingDaemon() {
     try {
       $this->cron_helper->accessDaemon('some_token');
       $this->fail('An exception should have been thrown.');
@@ -124,7 +124,7 @@ class CronHelperTest extends \MailPoetTest {
     }
   }
 
-  function testItDetectsNotAccessibleDaemon() {
+  public function testItDetectsNotAccessibleDaemon() {
     $time = time();
     $run_start_values = [null, $time - 20];
     foreach ($run_start_values as $run_start) {
@@ -139,7 +139,7 @@ class CronHelperTest extends \MailPoetTest {
     }
   }
 
-  function testItDetectsAccessibleDaemon() {
+  public function testItDetectsAccessibleDaemon() {
     $time = time();
     $daemon = $this->getDeamonTestData();
     $daemon['run_accessed_at'] = $time - 5;
@@ -151,7 +151,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($this->cron_helper->isDaemonAccessible())->true();
   }
 
-  function testItDetectsUnknownStateOfTheDaemon() {
+  public function testItDetectsUnknownStateOfTheDaemon() {
     $time = time();
     $test_inputs = [
       [
@@ -180,7 +180,7 @@ class CronHelperTest extends \MailPoetTest {
     }
   }
 
-  function testItDeactivatesDaemon() {
+  public function testItDeactivatesDaemon() {
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
@@ -192,7 +192,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($daemon['status'])->equals(CronHelper::DAEMON_STATUS_INACTIVE);
   }
 
-  function testItSavesLastError() {
+  public function testItSavesLastError() {
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
@@ -207,7 +207,7 @@ class CronHelperTest extends \MailPoetTest {
   }
 
 
-  function testItSavesRunCompletedAt() {
+  public function testItSavesRunCompletedAt() {
     $daemon = $this->getDeamonTestData();
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
@@ -219,7 +219,7 @@ class CronHelperTest extends \MailPoetTest {
     expect($daemon['run_completed_at'])->equals(123);
   }
 
-  function testItCreatesRandomToken() {
+  public function testItCreatesRandomToken() {
     // random token is a string of 5 characters
     $token1 = $this->cron_helper->createToken();
     $token2 = $this->cron_helper->createToken();
@@ -228,7 +228,7 @@ class CronHelperTest extends \MailPoetTest {
     expect(strlen($token1))->equals(5);
   }
 
-  function testItGetsSiteUrl() {
+  public function testItGetsSiteUrl() {
     // 1. do nothing when the url does not contain port
     $site_url = 'http://example.com';
     expect($this->cron_helper->getSiteUrl($site_url))->equals($site_url);
@@ -254,13 +254,13 @@ class CronHelperTest extends \MailPoetTest {
     }
   }
 
-  function testItGetsSubsiteUrlOnMultisiteEnvironment() {
+  public function testItGetsSubsiteUrlOnMultisiteEnvironment() {
     if ((boolean)getenv('MULTISITE') === true) {
       expect($this->cron_helper->getSiteUrl())->contains(getenv('WP_TEST_MULTISITE_SLUG'));
     }
   }
 
-  function testItEnforcesExecutionLimit() {
+  public function testItEnforcesExecutionLimit() {
     $time = microtime(true);
     expect($this->cron_helper->enforceExecutionLimit($time))->null();
     try {
@@ -271,7 +271,7 @@ class CronHelperTest extends \MailPoetTest {
     }
   }
 
-  function testItAllowsSettingCustomCronUrl() {
+  public function testItAllowsSettingCustomCronUrl() {
     $filter = function($url) {
       expect($url)->contains('&endpoint=cron');
       return 'http://custom_cron_url';
@@ -281,7 +281,7 @@ class CronHelperTest extends \MailPoetTest {
     remove_filter('mailpoet_cron_request_url', $filter);
   }
 
-  function testItAllowsSettingCustomCronRequestArguments() {
+  public function testItAllowsSettingCustomCronRequestArguments() {
     $request_args = [
       'blocking' => 'custom_blocking',
       'sslverify' => 'custom_ssl_verify',
@@ -306,7 +306,7 @@ class CronHelperTest extends \MailPoetTest {
     $wp->removeFilter('mailpoet_cron_request_args', $filter);
   }
 
-  function testItReturnsErrorMessageAsPingResponseWhenCronUrlCannotBeAccessed() {
+  public function testItReturnsErrorMessageAsPingResponseWhenCronUrlCannotBeAccessed() {
     $wp = Stub::make(new WPFunctions, [
       'applyFilters' => [],
     ]);
@@ -314,18 +314,18 @@ class CronHelperTest extends \MailPoetTest {
     expect($cron_helper->pingDaemon())->equals('A valid URL was not provided.');
   }
 
-  function testItPingsDaemon() {
+  public function testItPingsDaemon() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     // raw response is returned
     expect($this->cron_helper->pingDaemon())->equals(DaemonHttpRunner::PING_SUCCESS_RESPONSE);
   }
 
-  function testItValidatesPingResponse() {
+  public function testItValidatesPingResponse() {
     expect($this->cron_helper->validatePingResponse('pong'))->true();
     expect($this->cron_helper->validatePingResponse('something else'))->false();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 
diff --git a/tests/integration/Cron/CronWorkerRunnerTest.php b/tests/integration/Cron/CronWorkerRunnerTest.php
index ff13216c7e..22118373ff 100644
--- a/tests/integration/Cron/CronWorkerRunnerTest.php
+++ b/tests/integration/Cron/CronWorkerRunnerTest.php
@@ -20,13 +20,13 @@ class CronWorkerRunnerTest extends \MailPoetTest {
   /** @var CronHelper */
   private $cron_helper;
 
-  function _before() {
+  public function _before() {
     $this->cron_worker_runner = $this->di_container->get(CronWorkerRunner::class);
     $this->cron_helper = $this->di_container->get(CronHelper::class);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 
-  function testItCanInitBeforeProcessing() {
+  public function testItCanInitBeforeProcessing() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'init' => Expected::once(),
       'scheduleAutomatically' => Expected::once(false),
@@ -34,7 +34,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     $this->cron_worker_runner->run($worker);
   }
 
-  function testItPreparesTask() {
+  public function testItPreparesTask() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'prepareTaskStrategy' => Expected::once(true),
       'processTaskStrategy' => Expected::never(),
@@ -46,7 +46,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect(ScheduledTask::findOne($task->id)->status)->null();
   }
 
-  function testItProcessesTask() {
+  public function testItProcessesTask() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'prepareTaskStrategy' => Expected::never(),
       'processTaskStrategy' => Expected::once(true),
@@ -58,7 +58,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect(ScheduledTask::findOne($task->id)->status)->same(ScheduledTask::STATUS_COMPLETED);
   }
 
-  function testItFailsToProcessWithoutTasks() {
+  public function testItFailsToProcessWithoutTasks() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'scheduleAutomatically' => Expected::once(false),
       'prepareTaskStrategy' => Expected::never(),
@@ -69,7 +69,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItFailsToProcessWithoutProcessingRequirementsMet() {
+  public function testItFailsToProcessWithoutProcessingRequirementsMet() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'checkProcessingRequirements' => Expected::once(false),
       'prepareTaskStrategy' => Expected::never(),
@@ -83,7 +83,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItCanScheduleTaskAutomatically() {
+  public function testItCanScheduleTaskAutomatically() {
     $in_one_week = Carbon::now()->addWeek()->startOfDay();
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'scheduleAutomatically' => Expected::once(true),
@@ -96,7 +96,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect(ScheduledTask::findOne()->scheduled_at)->same($in_one_week->format('Y-m-d H:i:s'));
   }
 
-  function testItWillRescheduleTaskIfItIsRunningForTooLong() {
+  public function testItWillRescheduleTaskIfItIsRunningForTooLong() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'processTaskStrategy' => Expected::once(false),
     ]);
@@ -122,7 +122,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     expect($task->in_progress)->isEmpty();
   }
 
-  function testItWillRescheduleATaskIfItFails() {
+  public function testItWillRescheduleATaskIfItFails() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'processTaskStrategy' => Expected::once(function () {
         throw new \Exception('test error');
@@ -144,7 +144,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     }
   }
 
-  function testWillNotRescheduleATaskOnCronTimeout() {
+  public function testWillNotRescheduleATaskOnCronTimeout() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'processTaskStrategy' => Expected::once(function () {
         $this->cron_helper->enforceExecutionLimit(microtime(true) - CronHelper::DAEMON_EXECUTION_LIMIT - 1);
@@ -165,7 +165,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     }
   }
 
-  function testItWillNotRunInMultipleInstances() {
+  public function testItWillNotRunInMultipleInstances() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'supportsMultipleInstances' => Expected::once(false),
       'processTaskStrategy' => Expected::never(),
@@ -178,7 +178,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     $this->cron_worker_runner->run($worker);
   }
 
-  function testItThrowsExceptionWhenExecutionLimitIsReached() {
+  public function testItThrowsExceptionWhenExecutionLimitIsReached() {
     $worker = $this->make(SimpleWorkerMockImplementation::class, [
       'processTaskStrategy' => Expected::never(),
     ]);
@@ -212,7 +212,7 @@ class CronWorkerRunnerTest extends \MailPoetTest {
     return $task;
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 }
diff --git a/tests/integration/Cron/CronWorkerSchedulerTest.php b/tests/integration/Cron/CronWorkerSchedulerTest.php
index 3a85a0c06c..34a6ab47d0 100644
--- a/tests/integration/Cron/CronWorkerSchedulerTest.php
+++ b/tests/integration/Cron/CronWorkerSchedulerTest.php
@@ -13,12 +13,12 @@ class CronWorkerSchedulerTest extends \MailPoetTest {
   /** @var CronWorkerScheduler */
   private $cron_worker_scheduler;
 
-  function _before() {
+  public function _before() {
     $this->cron_worker_scheduler = $this->di_container->get(CronWorkerScheduler::class);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 
-  function testItSchedulesTask() {
+  public function testItSchedulesTask() {
     $next_run_date = Carbon::now()->addWeek();
     $this->cron_worker_scheduler->schedule('test', $next_run_date);
 
@@ -29,7 +29,7 @@ class CronWorkerSchedulerTest extends \MailPoetTest {
     expect($tasks[0]->scheduled_at)->same($next_run_date->format('Y-m-d H:i:s'));
   }
 
-  function testItDoesNotScheduleTaskTwice() {
+  public function testItDoesNotScheduleTaskTwice() {
     $next_run_date = Carbon::now()->addWeek();
     $this->cron_worker_scheduler->schedule('test', $next_run_date);
     expect(ScheduledTask::findMany())->count(1);
@@ -39,7 +39,7 @@ class CronWorkerSchedulerTest extends \MailPoetTest {
     expect(ScheduledTask::findMany())->count(1);
   }
 
-  function testItReschedulesTask() {
+  public function testItReschedulesTask() {
     $next_run_date = Carbon::now()->subDay();
     $task = $this->cron_worker_scheduler->schedule('test', $next_run_date);
     $this->cron_worker_scheduler->reschedule($task, 10);
@@ -52,7 +52,7 @@ class CronWorkerSchedulerTest extends \MailPoetTest {
     expect($tasks[0]->scheduled_at)->greaterThan(Carbon::now());
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 }
diff --git a/tests/integration/Cron/DaemonHttpRunnerTest.php b/tests/integration/Cron/DaemonHttpRunnerTest.php
index f9e25b2adc..5fed2f5741 100644
--- a/tests/integration/Cron/DaemonHttpRunnerTest.php
+++ b/tests/integration/Cron/DaemonHttpRunnerTest.php
@@ -23,13 +23,13 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->cron_helper = ContainerWrapper::getInstance()->get(CronHelper::class);
   }
 
-  function testItConstructs() {
+  public function testItConstructs() {
     $this->settings->set(
       CronHelper::DAEMON_SETTING,
       []
@@ -39,7 +39,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect(strlen($daemon->token))->greaterOrEquals(5);
   }
 
-  function testItDoesNotRunWithoutRequestData() {
+  public function testItDoesNotRunWithoutRequestData() {
     $daemon = $this->make(
       DaemonHttpRunner::class,
       [
@@ -51,7 +51,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($daemon->run(false))->equals('Invalid or missing request data.');
   }
 
-  function testItDoesNotRunWhenThereIsInvalidOrMissingToken() {
+  public function testItDoesNotRunWhenThereIsInvalidOrMissingToken() {
     $daemon = $this->make(
       DaemonHttpRunner::class,
       [
@@ -66,7 +66,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($daemon->run(['token' => 456]))->equals('Invalid or missing token.');
   }
 
-  function testItStoresErrorMessageAndContinuesExecutionWhenWorkersThrowException() {
+  public function testItStoresErrorMessageAndContinuesExecutionWhenWorkersThrowException() {
     $data = [
       'token' => 123,
     ];
@@ -94,7 +94,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($updated_daemon['last_error'][1]['message'])->equals('');
   }
 
-  function testItCanPauseExecution() {
+  public function testItCanPauseExecution() {
     $daemon = $this->makeEmpty(Daemon::class);
     $daemon_http_runner = $this->make(DaemonHttpRunner::class, [
       'pauseExecution' => Expected::exactly(1, function($pause_delay) {
@@ -113,7 +113,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
   }
 
 
-  function testItTerminatesExecutionWhenDaemonIsDeleted() {
+  public function testItTerminatesExecutionWhenDaemonIsDeleted() {
     $daemon = $this->make(Daemon::class, [
       'run' => function () {
         $this->settings->delete(CronHelper::DAEMON_SETTING);
@@ -134,7 +134,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     $daemon_http_runner->run($data);
   }
 
-  function testItTerminatesExecutionWhenDaemonTokenChangesAndKeepsChangedToken() {
+  public function testItTerminatesExecutionWhenDaemonTokenChangesAndKeepsChangedToken() {
     $daemon_http_runner = $this->make(DaemonHttpRunner::class, [
       'pauseExecution' => null,
       'terminateRequest' => Expected::exactly(1),
@@ -159,7 +159,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($data_after_run['token'])->equals(567);
   }
 
-  function testItTerminatesExecutionWhenDaemonIsDeactivated() {
+  public function testItTerminatesExecutionWhenDaemonIsDeactivated() {
     $daemon = $this->make(DaemonHttpRunner::class, [
       'pauseExecution' => null,
       'terminateRequest' => Expected::exactly(1),
@@ -174,7 +174,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     $daemon->run($data);
   }
 
-  function testItTerminatesExecutionWhenWPTriggerStopsCron() {
+  public function testItTerminatesExecutionWhenWPTriggerStopsCron() {
     $daemon = $this->make(Daemon::class, [
       'run' => null,
     ]);
@@ -195,7 +195,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     WPFunctions::get()->removeAllFilters('mailpoet_cron_enable_self_deactivation');
   }
 
-  function testItUpdatesDaemonTokenDuringExecution() {
+  public function testItUpdatesDaemonTokenDuringExecution() {
     $daemon_http_runner = $this->make(DaemonHttpRunner::class, [
       'pauseExecution' => null,
       'callSelf' => null,
@@ -215,7 +215,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($updated_daemon['token'])->equals($daemon_http_runner->token);
   }
 
-  function testItUpdatesTimestampsDuringExecution() {
+  public function testItUpdatesTimestampsDuringExecution() {
     $cron_worker_runner_mock = $this->createMock(CronWorkerRunner::class);
     $cron_worker_runner_mock
       ->expects($this->at(0))
@@ -247,7 +247,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect($updated_daemon['run_completed_at'])->lessThan($now + 4);
   }
 
-  function testItCanRun() {
+  public function testItCanRun() {
     ignore_user_abort(0);
     expect(ignore_user_abort())->equals(0);
     $daemon_http_runner = $this->make(DaemonHttpRunner::class, [
@@ -270,7 +270,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     expect(ignore_user_abort())->equals(1);
   }
 
-  function testItRespondsToPingRequest() {
+  public function testItRespondsToPingRequest() {
     $daemon = $this->make(DaemonHttpRunner::class, [
       'terminateRequest' => Expected::exactly(1, function($message) {
         expect($message)->equals('pong');
@@ -279,7 +279,7 @@ class DaemonHttpRunnerTest extends \MailPoetTest {
     $daemon->ping();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 
diff --git a/tests/integration/Cron/DaemonTest.php b/tests/integration/Cron/DaemonTest.php
index 7c9a40c0c7..d2055cdc43 100644
--- a/tests/integration/Cron/DaemonTest.php
+++ b/tests/integration/Cron/DaemonTest.php
@@ -23,7 +23,7 @@ class DaemonTest extends \MailPoetTest {
     $this->cron_helper = ContainerWrapper::getInstance()->get(CronHelper::class);
   }
 
-  function testItCanRun() {
+  public function testItCanRun() {
     $cron_worker_runner = $this->make(CronWorkerRunner::class, [
       'run' => null,
     ]);
@@ -35,7 +35,7 @@ class DaemonTest extends \MailPoetTest {
     $daemon->run($data);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 
diff --git a/tests/integration/Cron/SupervisorTest.php b/tests/integration/Cron/SupervisorTest.php
index 1c42afeba1..2441850a46 100644
--- a/tests/integration/Cron/SupervisorTest.php
+++ b/tests/integration/Cron/SupervisorTest.php
@@ -12,7 +12,7 @@ class SupervisorTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // cron trigger is by default set to 'WordPress'; when it runs and does not
     // detect any queues to process, it deletes the daemon setting, so Supervisor and
@@ -26,34 +26,34 @@ class SupervisorTest extends \MailPoetTest {
     $this->supervisor = ContainerWrapper::getInstance()->get(Supervisor::class);
   }
 
-  function testItCanBeInitialized() {
+  public function testItCanBeInitialized() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $this->supervisor->init();
     expect($this->supervisor->token)->notEmpty();
     expect($this->supervisor->daemon)->notEmpty();
   }
 
-  function testItCreatesDaemonWhenOneDoesNotExist() {
+  public function testItCreatesDaemonWhenOneDoesNotExist() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $this->supervisor->init();
     expect($this->supervisor->getDaemon())->notEmpty();
   }
 
-  function testItReturnsDaemonWhenOneExists() {
+  public function testItReturnsDaemonWhenOneExists() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $this->supervisor->init();
     expect($this->supervisor->getDaemon())->equals($this->supervisor->daemon);
   }
 
-  function testItDoesNothingWhenDaemonExecutionDurationIsBelowLimit() {
+  public function testItDoesNothingWhenDaemonExecutionDurationIsBelowLimit() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $this->supervisor->init();
     expect($this->supervisor->checkDaemon())
       ->equals($this->supervisor->daemon);
   }
 
-  function testRestartsDaemonWhenExecutionDurationIsAboveLimit() {
+  public function testRestartsDaemonWhenExecutionDurationIsAboveLimit() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $this->supervisor->init();
     $this->supervisor->daemon['updated_at'] = time() - $this->cron_helper->getDaemonExecutionTimeout();
@@ -63,7 +63,7 @@ class SupervisorTest extends \MailPoetTest {
     expect($daemon['status'])->equals(CronHelper::DAEMON_STATUS_ACTIVE);
   }
 
-  function testRestartsDaemonWhenItIsInactive() {
+  public function testRestartsDaemonWhenItIsInactive() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $this->supervisor->init();
     $this->supervisor->daemon['updated_at'] = time();
@@ -72,7 +72,7 @@ class SupervisorTest extends \MailPoetTest {
     expect($daemon['status'])->equals(CronHelper::DAEMON_STATUS_ACTIVE);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Cron/Triggers/MailPoetTest.php b/tests/integration/Cron/Triggers/MailPoetTest.php
index 2056d79fbf..5d850be48e 100644
--- a/tests/integration/Cron/Triggers/MailPoetTest.php
+++ b/tests/integration/Cron/Triggers/MailPoetTest.php
@@ -11,7 +11,7 @@ class MailPoetTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // cron trigger is by default set to 'WordPress'; when it runs and does not
     // detect any queues to process, it deletes the daemon setting, so Supervisor that's
@@ -23,13 +23,13 @@ class MailPoetTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanRun() {
+  public function testItCanRun() {
     expect($this->settings->get(CronHelper::DAEMON_SETTING))->null();
     $this->di_container->get(MailPoet::class)->run();
     expect($this->settings->get(CronHelper::DAEMON_SETTING))->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Cron/Triggers/WordPressTest.php b/tests/integration/Cron/Triggers/WordPressTest.php
index 5e1a215259..cbee80fa33 100644
--- a/tests/integration/Cron/Triggers/WordPressTest.php
+++ b/tests/integration/Cron/Triggers/WordPressTest.php
@@ -27,7 +27,7 @@ class WordPressTest extends \MailPoetTest {
   /** @var WordPress */
   private $wordpress_trigger;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // cron trigger is by default set to 'WordPress'; when it runs and does not
     // detect any queues to process, it deletes the daemon setting, so Supervisor that's
@@ -42,7 +42,7 @@ class WordPressTest extends \MailPoetTest {
     $this->wordpress_trigger = $this->di_container->get(WordPress::class);
   }
 
-  function testItDoesNotRunIfRunIntervalIsNotElapsed() {
+  public function testItDoesNotRunIfRunIntervalIsNotElapsed() {
     $run_interval = 10;
     WPFunctions::get()->addFilter('mailpoet_cron_trigger_wordpress_run_interval', function () use ($run_interval) {
       return $run_interval;
@@ -55,7 +55,7 @@ class WordPressTest extends \MailPoetTest {
     WPFunctions::get()->removeAllFilters('mailpoet_cron_trigger_wordpress_run_interval');
   }
 
-  function testItRunsIfRunIntervalIsElapsed() {
+  public function testItRunsIfRunIntervalIsElapsed() {
     $run_interval = 10;
     WPFunctions::get()->addFilter('mailpoet_cron_trigger_wordpress_run_interval', function () use ($run_interval) {
       return $run_interval;
@@ -68,7 +68,7 @@ class WordPressTest extends \MailPoetTest {
     WPFunctions::get()->removeAllFilters('mailpoet_cron_trigger_wordpress_run_interval');
   }
 
-  function testItCanResetRunInterval() {
+  public function testItCanResetRunInterval() {
     $current_time = time();
     $this->settings->set(WordPress::LAST_RUN_AT_SETTING, $current_time);
     $this->_addQueue($status = SendingQueue::STATUS_SCHEDULED);
@@ -77,13 +77,13 @@ class WordPressTest extends \MailPoetTest {
     expect($this->wordpress_trigger->run())->notEmpty();
   }
 
-  function testItRequiresScheduledQueuesToExecute() {
+  public function testItRequiresScheduledQueuesToExecute() {
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
     $this->_addQueue($status = SendingQueue::STATUS_SCHEDULED);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItRequiresRunningQueuesToExecute() {
+  public function testItRequiresRunningQueuesToExecute() {
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
     // status of 'null' indicates that queue is running
     $this->_addQueue($status = null);
@@ -91,13 +91,13 @@ class WordPressTest extends \MailPoetTest {
   }
 
 
-  function testItFailsExecutionRequiremenetsCheckWhenQueueStatusIsCompleted() {
+  public function testItFailsExecutionRequiremenetsCheckWhenQueueStatusIsCompleted() {
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
     $this->_addQueue($status = 'completed');
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
   }
 
-  function testItRequiresSendingLimitNotToBeReachedToExecute() {
+  public function testItRequiresSendingLimitNotToBeReachedToExecute() {
     $this->_addQueue($status = null);
     $this->_addMTAConfigAndLog($sent = null);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
@@ -105,7 +105,7 @@ class WordPressTest extends \MailPoetTest {
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
   }
 
-  function testItRequiresSendingNotToBePausedToExecute() {
+  public function testItRequiresSendingNotToBePausedToExecute() {
     $this->_addQueue($status = null);
     $this->_addMTAConfigAndLog($sent = null);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
@@ -113,36 +113,36 @@ class WordPressTest extends \MailPoetTest {
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
   }
 
-  function testItExecutesWhenMigrationIsNotPresent() {
+  public function testItExecutesWhenMigrationIsNotPresent() {
     $this->_enableMigration();
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItExecutesWhenMigrationIsDue() {
+  public function testItExecutesWhenMigrationIsDue() {
     $this->_enableMigration();
     $this->_addScheduledTask(MigrationWorker::TASK_TYPE, $status = ScheduledTask::STATUS_SCHEDULED);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItExecutesWhenAuthorizedEmailsCheckIsDue() {
+  public function testItExecutesWhenAuthorizedEmailsCheckIsDue() {
     $this->_enableMigration();
     $this->_addScheduledTask(AuthorizedSendingEmailsCheck::TASK_TYPE, $status = ScheduledTask::STATUS_SCHEDULED);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItExecutesWhenBeamerTaskIsDue() {
+  public function testItExecutesWhenBeamerTaskIsDue() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     $this->_addScheduledTask(Beamer::TASK_TYPE, $status = ScheduledTask::STATUS_SCHEDULED);
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItDoesNotExecuteWhenMigrationIsCompleted() {
+  public function testItDoesNotExecuteWhenMigrationIsCompleted() {
     $this->_enableMigration();
     $this->_addScheduledTask(MigrationWorker::TASK_TYPE, $status = ScheduledTask::STATUS_COMPLETED);
     expect($this->wordpress_trigger->checkExecutionRequirements())->false();
   }
 
-  function testItExecutesWhenBounceIsActive() {
+  public function testItExecutesWhenBounceIsActive() {
     $this->settings->set(Mailer::MAILER_CONFIG_SETTING_NAME, [
       'method' => Mailer::METHOD_MAILPOET,
       'frequency' => [
@@ -154,14 +154,14 @@ class WordPressTest extends \MailPoetTest {
     expect($this->wordpress_trigger->checkExecutionRequirements())->true();
   }
 
-  function testItCanDeactivateRunningDaemon() {
+  public function testItCanDeactivateRunningDaemon() {
     $this->settings->set(CronHelper::DAEMON_SETTING, ['status' => CronHelper::DAEMON_STATUS_ACTIVE]);
     expect($this->settings->get(CronHelper::DAEMON_SETTING)['status'])->equals(CronHelper::DAEMON_STATUS_ACTIVE);
     $this->wordpress_trigger->stop();
     expect($this->settings->get(CronHelper::DAEMON_SETTING)['status'])->equals(CronHelper::DAEMON_STATUS_INACTIVE);
   }
 
-  function testItRunsWhenExecutionRequirementsAreMet() {
+  public function testItRunsWhenExecutionRequirementsAreMet() {
     // status of 'null' indicates that queue is running
     $this->_addQueue($status = null);
     // check that cron daemon does not exist
@@ -170,14 +170,14 @@ class WordPressTest extends \MailPoetTest {
     expect($this->settings->get(CronHelper::DAEMON_SETTING))->notNull();
   }
 
-  function testItDeactivatesCronDaemonWhenExecutionRequirementsAreNotMet() {
+  public function testItDeactivatesCronDaemonWhenExecutionRequirementsAreNotMet() {
     $this->settings->set(CronHelper::DAEMON_SETTING, ['status' => CronHelper::DAEMON_STATUS_ACTIVE]);
     expect($this->settings->get(CronHelper::DAEMON_SETTING)['status'])->equals(CronHelper::DAEMON_STATUS_ACTIVE);
     $this->wordpress_trigger->run();
     expect($this->settings->get(CronHelper::DAEMON_SETTING)['status'])->equals(CronHelper::DAEMON_STATUS_INACTIVE);
   }
 
-  function _addMTAConfigAndLog($sent, $status = null) {
+  public function _addMTAConfigAndLog($sent, $status = null) {
     $mta_config = [
       'frequency' => [
         'emails' => 1,
@@ -199,7 +199,7 @@ class WordPressTest extends \MailPoetTest {
     );
   }
 
-  function _addQueue($status) {
+  public function _addQueue($status) {
     $queue = SendingTask::create();
     $queue->hydrate(
       [
@@ -213,7 +213,7 @@ class WordPressTest extends \MailPoetTest {
     return $queue->save();
   }
 
-  function _addScheduledTask($type, $status, $scheduled_at = null) {
+  public function _addScheduledTask($type, $status, $scheduled_at = null) {
     if (!$scheduled_at && $status === ScheduledTask::STATUS_SCHEDULED) {
       $scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
     }
@@ -228,7 +228,7 @@ class WordPressTest extends \MailPoetTest {
     return $task->save();
   }
 
-  function _enableMigration() {
+  public function _enableMigration() {
     // Migration can be triggered only if cron execution method is selected
     // and is not "none"
     $this->settings->set('cron_trigger', [
@@ -236,7 +236,7 @@ class WordPressTest extends \MailPoetTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Cron/Workers/AuthorizedSendingEmailsCheckTest.php b/tests/integration/Cron/Workers/AuthorizedSendingEmailsCheckTest.php
index eafa8aa0a9..2428e4829b 100644
--- a/tests/integration/Cron/Workers/AuthorizedSendingEmailsCheckTest.php
+++ b/tests/integration/Cron/Workers/AuthorizedSendingEmailsCheckTest.php
@@ -9,12 +9,12 @@ use MailPoet\Services\AuthorizedEmailsController;
 use MailPoetVendor\Idiorm\ORM;
 
 class AuthorizedSendingEmailsCheckTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 
-  function testItRunsCheckOnBridge() {
+  public function testItRunsCheckOnBridge() {
     $bridge_mock = $this->makeEmpty(AuthorizedEmailsController::class, ['checkAuthorizedEmailAddresses' => Stub\Expected::once()]);
     $worker = new AuthorizedSendingEmailsCheck($bridge_mock);
     $worker->processTaskStrategy(ScheduledTask::createOrUpdate([]), microtime(true));
diff --git a/tests/integration/Cron/Workers/BeamerTest.php b/tests/integration/Cron/Workers/BeamerTest.php
index 0e28fa4625..a5cac38fd8 100644
--- a/tests/integration/Cron/Workers/BeamerTest.php
+++ b/tests/integration/Cron/Workers/BeamerTest.php
@@ -10,7 +10,7 @@ use MailPoetVendor\Carbon\Carbon;
 
 class BeamerTest extends \MailPoetTest {
 
-  function testItSetsLastAnnouncementDate() {
+  public function testItSetsLastAnnouncementDate() {
     $oldDate = '2019-05-18T10:25:00.000Z';
     $newDate = '2019-05-22T10:25:00.000Z';
     $settings = SettingsController::getInstance();
@@ -27,7 +27,7 @@ class BeamerTest extends \MailPoetTest {
     expect($settings->get('last_announcement_date'))->equals(Carbon::createFromTimeString($newDate)->getTimestamp());
   }
 
-  function testItDoesNothingIfNoResponse() {
+  public function testItDoesNothingIfNoResponse() {
     $oldDate = '2019-05-18T10:25:00.000Z';
     $settings = SettingsController::getInstance();
     $settings->set('last_announcement_date', Carbon::createFromTimeString($oldDate)->getTimestamp());
@@ -41,7 +41,7 @@ class BeamerTest extends \MailPoetTest {
     expect($settings->get('last_announcement_date'))->equals(Carbon::createFromTimeString($oldDate)->getTimestamp());
   }
 
-  function testItDoesNothingIfWrongResponse() {
+  public function testItDoesNothingIfWrongResponse() {
     $oldDate = '2019-05-18T10:25:00.000Z';
     $settings = SettingsController::getInstance();
     $settings->set('last_announcement_date', Carbon::createFromTimeString($oldDate)->getTimestamp());
@@ -55,7 +55,7 @@ class BeamerTest extends \MailPoetTest {
     expect($settings->get('last_announcement_date'))->equals(Carbon::createFromTimeString($oldDate)->getTimestamp());
   }
 
-  function testItDoesNothingIfEmptyList() {
+  public function testItDoesNothingIfEmptyList() {
     $oldDate = '2019-05-18T10:25:00.000Z';
     $settings = SettingsController::getInstance();
     $settings->set('last_announcement_date', Carbon::createFromTimeString($oldDate)->getTimestamp());
diff --git a/tests/integration/Cron/Workers/BounceTest.php b/tests/integration/Cron/Workers/BounceTest.php
index 186795943b..01fdc3084a 100644
--- a/tests/integration/Cron/Workers/BounceTest.php
+++ b/tests/integration/Cron/Workers/BounceTest.php
@@ -17,7 +17,7 @@ use MailPoetVendor\Idiorm\ORM;
 require_once('BounceTestMockAPI.php');
 
 class BounceTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->emails = [
       'soft_bounce@example.com',
@@ -37,24 +37,24 @@ class BounceTest extends \MailPoetTest {
     $this->worker->api = new MockAPI('key');
   }
 
-  function testItDefinesConstants() {
+  public function testItDefinesConstants() {
     expect(Bounce::BATCH_SIZE)->equals(100);
   }
 
-  function testItCanInitializeBridgeAPI() {
+  public function testItCanInitializeBridgeAPI() {
     $this->setMailPoetSendingMethod();
     $worker = new Bounce($this->di_container->get(SettingsController::class), microtime(true));
     $worker->init();
     expect($worker->api instanceof API)->true();
   }
 
-  function testItRequiresMailPoetMethodToBeSetUp() {
+  public function testItRequiresMailPoetMethodToBeSetUp() {
     expect($this->worker->checkProcessingRequirements())->false();
     $this->setMailPoetSendingMethod();
     expect($this->worker->checkProcessingRequirements())->true();
   }
 
-  function testItDeletesAllSubscribersIfThereAreNoSubscribersToProcessWhenPreparingTask() {
+  public function testItDeletesAllSubscribersIfThereAreNoSubscribersToProcessWhenPreparingTask() {
     // 1st run - subscribers will be processed
     $task = $this->createScheduledTask();
     $this->worker->prepareTaskStrategy($task, microtime(true));
@@ -67,7 +67,7 @@ class BounceTest extends \MailPoetTest {
     expect(ScheduledTaskSubscriber::where('task_id', $task->id)->findMany())->isEmpty();
   }
 
-  function testItPreparesTask() {
+  public function testItPreparesTask() {
     $task = $this->createScheduledTask();
     expect(ScheduledTaskSubscriber::getUnprocessedCount($task->id))->isEmpty();
     $result = $this->worker->prepareTaskStrategy($task, microtime(true));
@@ -75,7 +75,7 @@ class BounceTest extends \MailPoetTest {
     expect(ScheduledTaskSubscriber::getUnprocessedCount($task->id))->notEmpty();
   }
 
-  function testItDeletesAllSubscribersIfThereAreNoSubscribersToProcessWhenProcessingTask() {
+  public function testItDeletesAllSubscribersIfThereAreNoSubscribersToProcessWhenProcessingTask() {
     // prepare subscribers
     $task = $this->createScheduledTask();
     $this->worker->prepareTaskStrategy($task, microtime(true));
@@ -88,7 +88,7 @@ class BounceTest extends \MailPoetTest {
     expect(ScheduledTaskSubscriber::where('task_id', $task->id)->findMany())->isEmpty();
   }
 
-  function testItProcessesTask() {
+  public function testItProcessesTask() {
     $task = $this->createRunningTask();
     $this->worker->prepareTaskStrategy($task, microtime(true));
     expect(ScheduledTaskSubscriber::getUnprocessedCount($task->id))->notEmpty();
@@ -96,7 +96,7 @@ class BounceTest extends \MailPoetTest {
     expect(ScheduledTaskSubscriber::getProcessedCount($task->id))->notEmpty();
   }
 
-  function testItSetsSubscriberStatusAsBounced() {
+  public function testItSetsSubscriberStatusAsBounced() {
     $emails = Subscriber::select('email')->findArray();
     $emails = array_column($emails, 'email');
 
@@ -138,7 +138,7 @@ class BounceTest extends \MailPoetTest {
     return $task;
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
diff --git a/tests/integration/Cron/Workers/BounceTestMockAPI.php b/tests/integration/Cron/Workers/BounceTestMockAPI.php
index 919f57f137..c93780176b 100644
--- a/tests/integration/Cron/Workers/BounceTestMockAPI.php
+++ b/tests/integration/Cron/Workers/BounceTestMockAPI.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Cron\Workers\Bounce;
 
 class BounceTestMockAPI {
-  function checkBounces(array $emails) {
+  public function checkBounces(array $emails) {
     return array_map(
       function ($email) {
         return [
diff --git a/tests/integration/Cron/Workers/ExportFilesCleanupTest.php b/tests/integration/Cron/Workers/ExportFilesCleanupTest.php
index 875033e15c..17105fbcdf 100644
--- a/tests/integration/Cron/Workers/ExportFilesCleanupTest.php
+++ b/tests/integration/Cron/Workers/ExportFilesCleanupTest.php
@@ -7,7 +7,7 @@ use MailPoet\Models\ScheduledTask;
 
 class ExportFilesCleanupTest extends \MailPoetTest {
 
-  function testItWorks() {
+  public function testItWorks() {
     $wp_upload_dir = wp_upload_dir();
     $old_file_path = $wp_upload_dir['basedir'] . '/mailpoet/MailPoet_export_old_file.csv';
     $new_file_path = $wp_upload_dir['basedir'] . '/mailpoet/MailPoet_export_new_file.csv';
diff --git a/tests/integration/Cron/Workers/InactiveSubscribersTest.php b/tests/integration/Cron/Workers/InactiveSubscribersTest.php
index b6b96e284f..81e1e3c9e9 100644
--- a/tests/integration/Cron/Workers/InactiveSubscribersTest.php
+++ b/tests/integration/Cron/Workers/InactiveSubscribersTest.php
@@ -17,7 +17,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     $this->settings = SettingsController::getInstance();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     $this->settings->set('tracking.enabled', true);
@@ -25,7 +25,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     parent::_before();
   }
 
-  function testItReactivateInactiveSubscribersWhenIntervalIsSetToNever() {
+  public function testItReactivateInactiveSubscribersWhenIntervalIsSetToNever() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 0);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
       'markInactiveSubscribers' => Stub\Expected::never(),
@@ -44,7 +44,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     expect($task->scheduled_at)->greaterThan(new Carbon());
   }
 
-  function testItDoesNotRunWhenTrackingIsDisabled() {
+  public function testItDoesNotRunWhenTrackingIsDisabled() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 10);
     $this->settings->set('tracking.enabled', false);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
@@ -57,7 +57,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     $worker->processTaskStrategy(ScheduledTask::createOrUpdate([]), microtime(true));
   }
 
-  function testItSchedulesNextRunWhenFinished() {
+  public function testItSchedulesNextRunWhenFinished() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 5);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
       'markInactiveSubscribers' => Stub\Expected::once(1),
@@ -76,7 +76,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     expect($task->scheduled_at)->greaterThan(new Carbon());
   }
 
-  function testRunBatchesUntilItIsFinished() {
+  public function testRunBatchesUntilItIsFinished() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 5);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
       'markInactiveSubscribers' => Stub::consecutive(InactiveSubscribers::BATCH_SIZE, InactiveSubscribers::BATCH_SIZE, 1, 'ok'),
@@ -93,7 +93,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     expect($controller_mock->markActiveSubscribers(5, 1000))->equals('ok');
   }
 
-  function testItCanStopDeactivationIfMarkInactiveSubscribersReturnsFalse() {
+  public function testItCanStopDeactivationIfMarkInactiveSubscribersReturnsFalse() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 5);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
       'markInactiveSubscribers' => Stub\Expected::once(false),
@@ -110,7 +110,7 @@ class InactiveSubscribersTest extends \MailPoetTest {
     expect(isset($meta['last_subscriber_id']))->equals(false);
   }
 
-  function testThrowsAnExceptionWhenTimeIsOut() {
+  public function testThrowsAnExceptionWhenTimeIsOut() {
     $this->settings->set('deactivate_subscriber_after_inactive_days', 5);
     $controller_mock = Stub::make(InactiveSubscribersController::class, [
       'markInactiveSubscribers' => Stub\Expected::once(InactiveSubscribers::BATCH_SIZE),
diff --git a/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerMockImplementation.php b/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerMockImplementation.php
index 298b6443f0..570fe391bc 100644
--- a/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerMockImplementation.php
+++ b/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerMockImplementation.php
@@ -5,7 +5,7 @@ namespace MailPoet\Cron\Workers\KeyCheck;
 class KeyCheckWorkerMockImplementation extends KeyCheckWorker {
   const TASK_TYPE = 'mock_key_check_worker';
 
-  function checkKey() {
+  public function checkKey() {
     return ['code' => 12345]; // bogus code
   }
 }
diff --git a/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerTest.php b/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerTest.php
index 69f4e5760b..5189e451b3 100644
--- a/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerTest.php
+++ b/tests/integration/Cron/Workers/KeyCheck/KeyCheckWorkerTest.php
@@ -14,23 +14,23 @@ use MailPoetVendor\Idiorm\ORM;
 require_once('KeyCheckWorkerMockImplementation.php');
 
 class KeyCheckWorkerTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->worker = new MockKeyCheckWorker();
   }
 
-  function testItCanInitializeBridgeAPI() {
+  public function testItCanInitializeBridgeAPI() {
     $this->worker->init();
     expect($this->worker->bridge instanceof Bridge)->true();
   }
 
-  function testItReturnsTrueOnSuccessfulKeyCheck() {
+  public function testItReturnsTrueOnSuccessfulKeyCheck() {
     $task = $this->createRunningTask();
     $result = $this->worker->processTaskStrategy($task, microtime(true));
     expect($result)->true();
   }
 
-  function testItReschedulesCheckOnException() {
+  public function testItReschedulesCheckOnException() {
     $worker = Stub::make(
       $this->worker,
       [
@@ -49,7 +49,7 @@ class KeyCheckWorkerTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItReschedulesCheckOnError() {
+  public function testItReschedulesCheckOnError() {
     $worker = Stub::make(
       $this->worker,
       [
@@ -75,7 +75,7 @@ class KeyCheckWorkerTest extends \MailPoetTest {
     return $task;
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
diff --git a/tests/integration/Cron/Workers/KeyCheck/PremiumKeyCheckTest.php b/tests/integration/Cron/Workers/KeyCheck/PremiumKeyCheckTest.php
index d752509d80..09f9b9bd65 100644
--- a/tests/integration/Cron/Workers/KeyCheck/PremiumKeyCheckTest.php
+++ b/tests/integration/Cron/Workers/KeyCheck/PremiumKeyCheckTest.php
@@ -13,20 +13,20 @@ class PremiumKeyCheckTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->premium_key = '123457890abcdef';
     $this->worker = new PremiumKeyCheck($this->settings, microtime(true));
   }
 
-  function testItRequiresPremiumKeyToBeSpecified() {
+  public function testItRequiresPremiumKeyToBeSpecified() {
     expect($this->worker->checkProcessingRequirements())->false();
     $this->fillPremiumKey();
     expect($this->worker->checkProcessingRequirements())->true();
   }
 
-  function testItChecksPremiumKey() {
+  public function testItChecksPremiumKey() {
     $response = ['code' => Bridge::KEY_VALID];
     $this->worker->bridge = Stub::make(
       new Bridge,
@@ -56,7 +56,7 @@ class PremiumKeyCheckTest extends \MailPoetTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php b/tests/integration/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
index 208ac48f7a..d5de828039 100644
--- a/tests/integration/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
+++ b/tests/integration/Cron/Workers/KeyCheck/SendingServiceKeyCheckTest.php
@@ -11,19 +11,19 @@ use MailPoet\Settings\SettingsController;
 use MailPoet\Settings\SettingsRepository;
 
 class SendingServiceKeyCheckTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mss_key = 'some_key';
     $this->worker = new SendingServiceKeyCheck($this->di_container->get(SettingsController::class), microtime(true));
   }
 
-  function testItRequiresMailPoetMethodToBeSetUp() {
+  public function testItRequiresMailPoetMethodToBeSetUp() {
     expect($this->worker->checkProcessingRequirements())->false();
     $this->setMailPoetSendingMethod();
     expect($this->worker->checkProcessingRequirements())->true();
   }
 
-  function testItChecksMSSKey() {
+  public function testItChecksMSSKey() {
     $response = ['code' => Bridge::KEY_VALID];
     $this->worker->bridge = Stub::make(
       new Bridge,
@@ -58,7 +58,7 @@ class SendingServiceKeyCheckTest extends \MailPoetTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Cron/Workers/SchedulerTest.php b/tests/integration/Cron/Workers/SchedulerTest.php
index 5dc97642db..c6ec1456d4 100644
--- a/tests/integration/Cron/Workers/SchedulerTest.php
+++ b/tests/integration/Cron/Workers/SchedulerTest.php
@@ -29,13 +29,13 @@ class SchedulerTest extends \MailPoetTest {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->logger_factory = LoggerFactory::getInstance();
     $this->cron_helper = ContainerWrapper::getInstance()->get(CronHelper::class);
   }
 
-  function testItThrowsExceptionWhenExecutionLimitIsReached() {
+  public function testItThrowsExceptionWhenExecutionLimitIsReached() {
     try {
       $scheduler = new Scheduler($this->makeEmpty(SubscribersFinder::class), $this->logger_factory, $this->cron_helper);
       $scheduler->process(microtime(true) - $this->cron_helper->getDaemonExecutionLimit());
@@ -45,7 +45,7 @@ class SchedulerTest extends \MailPoetTest {
     }
   }
 
-  function testItCanGetScheduledQueues() {
+  public function testItCanGetScheduledQueues() {
     expect(Scheduler::getScheduledQueues())->isEmpty();
     $queue = SendingTask::create();
     $queue->newsletter_id = 1;
@@ -55,7 +55,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(Scheduler::getScheduledQueues())->notEmpty();
   }
 
-  function testItCanCreateNotificationHistory() {
+  public function testItCanCreateNotificationHistory() {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_NOTIFICATION;
     $newsletter->save();
@@ -75,7 +75,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($notification_history)->notEmpty();
   }
 
-  function testItCanDeleteQueueWhenDeliveryIsSetToImmediately() {
+  public function testItCanDeleteQueueWhenDeliveryIsSetToImmediately() {
     $newsletter = $this->_createNewsletter();
     $newsletter_option_field =
       $this->_createNewsletterOptionField('intervalType', Newsletter::TYPE_WELCOME);
@@ -91,7 +91,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItCanRescheduleQueueDeliveryTime() {
+  public function testItCanRescheduleQueueDeliveryTime() {
     $newsletter = $this->_createNewsletter();
     $newsletter_option_field =
       $this->_createNewsletterOptionField('intervalType', Newsletter::TYPE_WELCOME);
@@ -114,7 +114,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($queue->scheduled_at)->notNull();
   }
 
-  function testItFailsWPSubscriberVerificationWhenSubscriberIsNotAWPUser() {
+  public function testItFailsWPSubscriberVerificationWhenSubscriberIsNotAWPUser() {
     $WP_user = $this->_createOrUpdateWPUser('editor');
     $subscriber = $this->_createSubscriber();
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME);
@@ -137,7 +137,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItFailsWPSubscriberVerificationWhenSubscriberRoleDoesNotMatch() {
+  public function testItFailsWPSubscriberVerificationWhenSubscriberRoleDoesNotMatch() {
     $WP_user = $this->_createOrUpdateWPUser('editor');
     $subscriber = $this->_createSubscriber($WP_user->ID);
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME);
@@ -161,7 +161,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(count(SendingQueue::findMany()))->equals(0);
   }
 
-  function testItPassesWPSubscriberVerificationWhenSubscriberExistsAndRoleMatches() {
+  public function testItPassesWPSubscriberVerificationWhenSubscriberExistsAndRoleMatches() {
     $WP_user = $this->_createOrUpdateWPUser('author');
     $subscriber = $this->_createSubscriber($WP_user->ID);
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME);
@@ -182,7 +182,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(count(SendingQueue::findMany()))->greaterOrEquals(1);
   }
 
-  function testItPassesWPSubscriberVerificationWhenSubscriberHasAnyRole() {
+  public function testItPassesWPSubscriberVerificationWhenSubscriberHasAnyRole() {
     $WP_user = $this->_createOrUpdateWPUser('author');
     $subscriber = $this->_createSubscriber($WP_user->ID);
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME);
@@ -203,7 +203,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(count(SendingQueue::findMany()))->greaterOrEquals(1);
   }
 
-  function testItDoesNotProcessWelcomeNewsletterWhenThereAreNoSubscribersToProcess() {
+  public function testItDoesNotProcessWelcomeNewsletterWhenThereAreNoSubscribersToProcess() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
     $queue->setSubscribers([]);
@@ -215,7 +215,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItDoesNotProcessWelcomeNewsletterWhenWPUserCannotBeVerified() {
+  public function testItDoesNotProcessWelcomeNewsletterWhenWPUserCannotBeVerified() {
     $newsletter = $this->_createNewsletter();
     $newsletter->event = 'user';
     $queue = $this->_createQueue($newsletter->id);
@@ -230,7 +230,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($scheduler->processWelcomeNewsletter($newsletter, $queue))->false();
   }
 
-  function testItDoesNotProcessWelcomeNewsletterWhenSubscriberCannotBeVerified() {
+  public function testItDoesNotProcessWelcomeNewsletterWhenSubscriberCannotBeVerified() {
     $newsletter = $this->_createNewsletter();
     $newsletter->event = 'segment';
     $queue = $this->_createQueue($newsletter->id);
@@ -245,7 +245,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($scheduler->processWelcomeNewsletter($newsletter, $queue))->false();
   }
 
-  function testItProcessesWelcomeNewsletterWhenSubscriberIsVerified() {
+  public function testItProcessesWelcomeNewsletterWhenSubscriberIsVerified() {
     $newsletter = $this->_createNewsletter();
     $newsletter->event = 'segment';
 
@@ -261,7 +261,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($updated_queue->status)->null();
   }
 
-  function testItProcessesWelcomeNewsletterWhenWPUserIsVerified() {
+  public function testItProcessesWelcomeNewsletterWhenWPUserIsVerified() {
     $newsletter = $this->_createNewsletter();
     $newsletter->event = 'user';
 
@@ -278,7 +278,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($updated_queue->status)->null();
   }
 
-  function testItFailsMailpoetSubscriberVerificationWhenSubscriberDoesNotExist() {
+  public function testItFailsMailpoetSubscriberVerificationWhenSubscriberDoesNotExist() {
     $scheduler = new Scheduler($this->makeEmpty(SubscribersFinder::class), $this->logger_factory, $this->cron_helper);
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
@@ -290,7 +290,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItFailsMailpoetSubscriberVerificationWhenSubscriberIsNotInSegment() {
+  public function testItFailsMailpoetSubscriberVerificationWhenSubscriberIsNotInSegment() {
     $subscriber = $this->_createSubscriber();
     $segment = $this->_createSegment();
     $newsletter = $this->_createNewsletter();
@@ -308,7 +308,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItReschedulesQueueDeliveryWhenMailpoetSubscriberHasNotConfirmedSubscription() {
+  public function testItReschedulesQueueDeliveryWhenMailpoetSubscriberHasNotConfirmedSubscription() {
     $current_time = Carbon::createFromTimestamp(current_time('timestamp'));
     Carbon::setTestNow($current_time); // mock carbon to return current time
     $subscriber = $this->_createSubscriber($wp_user_id = null, 'unconfirmed');
@@ -337,7 +337,7 @@ class SchedulerTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesntRunQueueDeliveryWhenMailpoetSubscriberHasUnsubscribed() {
+  public function testItDoesntRunQueueDeliveryWhenMailpoetSubscriberHasUnsubscribed() {
     $current_time = Carbon::createFromTimestamp(current_time('timestamp'));
     Carbon::setTestNow($current_time); // mock carbon to return current time
     $subscriber = $this->_createSubscriber($wp_user_id = null, 'unsubscribed');
@@ -362,7 +362,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findOne($queue->id))->false();
   }
 
-  function testItCanVerifyMailpoetSubscriber() {
+  public function testItCanVerifyMailpoetSubscriber() {
     $subscriber = $this->_createSubscriber();
     $segment = $this->_createSegment();
     $subscriber_segment = $this->_createSubscriberSegment($subscriber->id, $segment->id);
@@ -383,7 +383,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($result)->true();
   }
 
-  function testItProcessesScheduledStandardNewsletter() {
+  public function testItProcessesScheduledStandardNewsletter() {
     $subscriber = $this->_createSubscriber();
     $segment = $this->_createSegment();
     $subscriber_segment = $this->_createSubscriberSegment($subscriber->id, $segment->id);
@@ -413,7 +413,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($updated_newsletter->status)->equals(Newsletter::STATUS_SENDING);
   }
 
-  function testItFailsToProcessPostNotificationNewsletterWhenSegmentsDontExist() {
+  public function testItFailsToProcessPostNotificationNewsletterWhenSegmentsDontExist() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
 
@@ -428,7 +428,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($scheduler->processPostNotificationNewsletter($newsletter, $queue))->false();
   }
 
-  function testItFailsToProcessPostNotificationNewsletterWhenSubscribersNotInSegment() {
+  public function testItFailsToProcessPostNotificationNewsletterWhenSubscribersNotInSegment() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
     $segment = $this->_createSegment();
@@ -443,7 +443,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($scheduler->processPostNotificationNewsletter($newsletter, $queue))->false();
   }
 
-  function testItCanProcessPostNotificationNewsletter() {
+  public function testItCanProcessPostNotificationNewsletter() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
     $segment = $this->_createSegment();
@@ -478,12 +478,12 @@ class SchedulerTest extends \MailPoetTest {
     expect($updated_notification_history->status)->equals(Newsletter::STATUS_SENDING);
   }
 
-  function testItFailsToProcessWhenScheduledQueuesNotFound() {
+  public function testItFailsToProcessWhenScheduledQueuesNotFound() {
     $scheduler = new Scheduler($this->makeEmpty(SubscribersFinder::class), $this->logger_factory, $this->cron_helper);
     expect($scheduler->process())->false();
   }
 
-  function testItDeletesQueueDuringProcessingWhenNewsletterNotFound() {
+  public function testItDeletesQueueDuringProcessingWhenNewsletterNotFound() {
     $queue = $this->_createQueue(1);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
     $queue->save();
@@ -492,7 +492,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItDeletesQueueDuringProcessingWhenNewsletterIsSoftDeleted() {
+  public function testItDeletesQueueDuringProcessingWhenNewsletterIsSoftDeleted() {
     $newsletter = $this->_createNewsletter();
     $newsletter->deleted_at = Carbon::createFromTimestamp(current_time('timestamp'));
     $newsletter->save();
@@ -504,7 +504,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItProcessesWelcomeNewsletters() {
+  public function testItProcessesWelcomeNewsletters() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME);
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -517,7 +517,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItProcessesNotificationNewsletters() {
+  public function testItProcessesNotificationNewsletters() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -530,7 +530,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItProcessesStandardScheduledNewsletters() {
+  public function testItProcessesStandardScheduledNewsletters() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_STANDARD);
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -543,7 +543,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItEnforcesExecutionLimitDuringProcessing() {
+  public function testItEnforcesExecutionLimitDuringProcessing() {
     $newsletter = $this->_createNewsletter();
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -557,7 +557,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItDoesNotProcessScheduledJobsWhenNewsletterIsNotActive() {
+  public function testItDoesNotProcessScheduledJobsWhenNewsletterIsNotActive() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_STANDARD, Newsletter::STATUS_DRAFT);
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -572,7 +572,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItProcessesScheduledJobsWhenNewsletterIsActive() {
+  public function testItProcessesScheduledJobsWhenNewsletterIsActive() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_STANDARD, Newsletter::STATUS_ACTIVE);
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -587,7 +587,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItReSchedulesBounceTask() {
+  public function testItReSchedulesBounceTask() {
     $task = ScheduledTask::createOrUpdate([
       'type' => 'bounce',
       'status' => ScheduledTask::STATUS_SCHEDULED,
@@ -603,7 +603,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($refetched_task->scheduled_at)->lessThan(Carbon::createFromTimestamp(current_time('timestamp'))->addHours(42));
   }
 
-  function testItDoesNotReSchedulesBounceTaskWhenSoon() {
+  public function testItDoesNotReSchedulesBounceTaskWhenSoon() {
     $task = ScheduledTask::createOrUpdate([
       'type' => 'bounce',
       'status' => ScheduledTask::STATUS_SCHEDULED,
@@ -619,7 +619,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($refetched_task->scheduled_at)->lessThan(Carbon::createFromTimestamp(current_time('timestamp'))->addHours(1));
   }
 
-  function testItProcessesScheduledJobsWhenNewsletterIsScheduled() {
+  public function testItProcessesScheduledJobsWhenNewsletterIsScheduled() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_STANDARD, Newsletter::STATUS_SCHEDULED);
     $queue = $this->_createQueue($newsletter->id);
     $queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -634,7 +634,7 @@ class SchedulerTest extends \MailPoetTest {
     $scheduler->process();
   }
 
-  function testItProcessesScheduledAutomaticEmailWhenSendingToUser() {
+  public function testItProcessesScheduledAutomaticEmailWhenSendingToUser() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_AUTOMATIC, Newsletter::STATUS_SCHEDULED);
     $subscriber = $this->_createSubscriber();
     $task = SendingTask::create();
@@ -657,7 +657,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($task->status)->null();
   }
 
-  function testItDeletesScheduledAutomaticEmailWhenUserDoesNotExist() {
+  public function testItDeletesScheduledAutomaticEmailWhenUserDoesNotExist() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_AUTOMATIC, Newsletter::STATUS_SCHEDULED);
     $subscriber = $this->_createSubscriber();
     $task = SendingTask::create();
@@ -681,7 +681,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($task)->false();
   }
 
-  function testItProcessesScheduledAutomaticEmailWhenSendingToSegment() {
+  public function testItProcessesScheduledAutomaticEmailWhenSendingToSegment() {
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_AUTOMATIC, Newsletter::STATUS_SCHEDULED);
     $segment = $this->_createSegment();
     $subscriber = $this->_createSubscriber();
@@ -713,7 +713,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($subscribers[0]->id)->equals($subscriber->id);
   }
 
-  function testItUpdatesUpdateTime() {
+  public function testItUpdatesUpdateTime() {
     $originalUpdated = Carbon::createFromTimestamp(current_time('timestamp'))->subHours(5)->toDateTimeString();
     $newsletter = $this->_createNewsletter(Newsletter::TYPE_WELCOME, Newsletter::STATUS_DRAFT);
     $queue = $this->_createQueue($newsletter->id);
@@ -727,7 +727,7 @@ class SchedulerTest extends \MailPoetTest {
     expect($newQueue->updated_at)->notEquals($originalUpdated);
   }
 
-  function _createNewsletterSegment($newsletter_id, $segment_id) {
+  public function _createNewsletterSegment($newsletter_id, $segment_id) {
     $newsletter_segment = NewsletterSegment::create();
     $newsletter_segment->newsletter_id = $newsletter_id;
     $newsletter_segment->segment_id = $segment_id;
@@ -736,7 +736,7 @@ class SchedulerTest extends \MailPoetTest {
     return $newsletter_segment;
   }
 
-  function _createSubscriberSegment($subscriber_id, $segment_id, $status = 'subscribed') {
+  public function _createSubscriberSegment($subscriber_id, $segment_id, $status = 'subscribed') {
     $subscriber_segment = SubscriberSegment::create();
     $subscriber_segment->subscriber_id = $subscriber_id;
     $subscriber_segment->segment_id = $segment_id;
@@ -746,7 +746,7 @@ class SchedulerTest extends \MailPoetTest {
     return $subscriber_segment;
   }
 
-  function _createSegment() {
+  public function _createSegment() {
     $segment = Segment::create();
     $segment->name = 'test';
     $segment->type = 'default';
@@ -755,7 +755,7 @@ class SchedulerTest extends \MailPoetTest {
     return $segment;
   }
 
-  function _createSubscriber($wp_user_id = null, $status = 'subscribed') {
+  public function _createSubscriber($wp_user_id = null, $status = 'subscribed') {
     $subscriber = Subscriber::create();
     $subscriber->email = 'john@doe.com';
     $subscriber->first_name = 'John';
@@ -767,7 +767,7 @@ class SchedulerTest extends \MailPoetTest {
     return $subscriber;
   }
 
-  function _createNewsletter($type = Newsletter::TYPE_NOTIFICATION, $status = 'active') {
+  public function _createNewsletter($type = Newsletter::TYPE_NOTIFICATION, $status = 'active') {
     $newsletter = Newsletter::create();
     $newsletter->type = $type;
     $newsletter->status = $status;
@@ -776,7 +776,7 @@ class SchedulerTest extends \MailPoetTest {
     return $newsletter;
   }
 
-  function _createNewsletterOptionField($name, $type) {
+  public function _createNewsletterOptionField($name, $type) {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = $name;
     $newsletter_option_field->newsletter_type = $type;
@@ -785,7 +785,7 @@ class SchedulerTest extends \MailPoetTest {
     return $newsletter_option_field;
   }
 
-  function _createNewsletterOption($option_field_id, $newsletter_id, $value) {
+  public function _createNewsletterOption($option_field_id, $newsletter_id, $value) {
     $newsletter_option = NewsletterOption::create();
     $newsletter_option->option_field_id = $option_field_id;
     $newsletter_option->newsletter_id = $newsletter_id;
@@ -795,7 +795,7 @@ class SchedulerTest extends \MailPoetTest {
     return $newsletter_option;
   }
 
-  function _createQueue($newsletter_id, $status = SendingQueue::STATUS_SCHEDULED) {
+  public function _createQueue($newsletter_id, $status = SendingQueue::STATUS_SCHEDULED) {
     $queue = SendingTask::create();
     $queue->status = $status;
     $queue->newsletter_id = $newsletter_id;
@@ -804,7 +804,7 @@ class SchedulerTest extends \MailPoetTest {
     return $queue;
   }
 
-  function _createOrUpdateWPUser($role = null) {
+  public function _createOrUpdateWPUser($role = null) {
     $email = 'test@example.com';
     $username = 'phoenix_test_user';
     if (email_exists($email) === false) {
@@ -827,7 +827,7 @@ class SchedulerTest extends \MailPoetTest {
     return $user;
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     $this->di_container->get(SettingsRepository::class)->truncate();
diff --git a/tests/integration/Cron/Workers/SendingQueue/MigrationTest.php b/tests/integration/Cron/Workers/SendingQueue/MigrationTest.php
index 922a9eea0a..ca3ad095fb 100644
--- a/tests/integration/Cron/Workers/SendingQueue/MigrationTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/MigrationTest.php
@@ -19,7 +19,7 @@ class MigrationTest extends \MailPoetTest {
   /** @var Migration */
   private $worker;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // Alter table to test migration
     $this->downgradeTable();
@@ -44,17 +44,17 @@ class MigrationTest extends \MailPoetTest {
     $this->worker = new Migration(microtime(true));
   }
 
-  function testItDefinesConstants() {
+  public function testItDefinesConstants() {
     expect(Migration::BATCH_SIZE)->equals(20);
   }
 
-  function testItChecksForACompletedMigrationBeforeRunning() {
+  public function testItChecksForACompletedMigrationBeforeRunning() {
     expect($this->worker->checkProcessingRequirements())->true();
     $this->createCompletedTask();
     expect($this->worker->checkProcessingRequirements())->false();
   }
 
-  function testItPausesSendingWhenPreparingATask() {
+  public function testItPausesSendingWhenPreparingATask() {
     $task = $this->createScheduledTask();
     expect(MailerLog::isSendingPaused())->false();
     $result = $this->worker->prepareTaskStrategy($task, microtime(true));
@@ -62,7 +62,7 @@ class MigrationTest extends \MailPoetTest {
     expect(MailerLog::isSendingPaused())->true();
   }
 
-  function testItResumesSendingIfThereIsNothingToMigrate() {
+  public function testItResumesSendingIfThereIsNothingToMigrate() {
     SendingQueue::deleteMany();
     $this->worker->pauseSending();
     expect(MailerLog::isSendingPaused())->true();
@@ -71,14 +71,14 @@ class MigrationTest extends \MailPoetTest {
     expect(MailerLog::isSendingPaused())->false();
   }
 
-  function testItCompletesTaskIfThereIsNothingToMigrate() {
+  public function testItCompletesTaskIfThereIsNothingToMigrate() {
     SendingQueue::deleteMany();
     $task = $this->createScheduledTask();
     $this->worker->prepareTaskStrategy($task, microtime(true));
     expect(ScheduledTask::findOne($task->id)->status)->equals(ScheduledTask::STATUS_COMPLETED);
   }
 
-  function testItMigratesSendingQueuesAndSubscribers() {
+  public function testItMigratesSendingQueuesAndSubscribers() {
     expect($this->worker->getUnmigratedQueues()->count())->equals(4);
     expect(ScheduledTask::where('type', SendingTask::TASK_TYPE)->findMany())->count(0);
     expect(ScheduledTaskSubscriber::whereGt('task_id', 0)->count())->equals(0);
@@ -102,7 +102,7 @@ class MigrationTest extends \MailPoetTest {
     expect($migrated_subscribers[1]->processed)->equals(ScheduledTaskSubscriber::STATUS_PROCESSED);
   }
 
-  function testItResumesSendingAfterMigratingSendingQueuesAndSubscribers() {
+  public function testItResumesSendingAfterMigratingSendingQueuesAndSubscribers() {
     $this->worker->pauseSending();
     expect(MailerLog::isSendingPaused())->true();
     $task = $this->createRunningTask();
@@ -110,7 +110,7 @@ class MigrationTest extends \MailPoetTest {
     expect(MailerLog::isSendingPaused())->false();
   }
 
-  function testItUsesWPTimeToReturnNextRunDate() {
+  public function testItUsesWPTimeToReturnNextRunDate() {
     $timestamp = 1514801410;
 
     $wp = Stub::make(new WPFunctions, [
@@ -191,7 +191,7 @@ class MigrationTest extends \MailPoetTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
diff --git a/tests/integration/Cron/Workers/SendingQueue/SendingErrorHandlerTest.php b/tests/integration/Cron/Workers/SendingQueue/SendingErrorHandlerTest.php
index 76232abe93..c36e5b7c88 100644
--- a/tests/integration/Cron/Workers/SendingQueue/SendingErrorHandlerTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/SendingErrorHandlerTest.php
@@ -14,12 +14,12 @@ class SendingErrorHandlerTest extends \MailPoetTest {
   /** @var SendingErrorHandler */
   private $error_handler;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->error_handler = new SendingErrorHandler();
   }
 
-  function testItShouldProcessSoftErrorCorrectly() {
+  public function testItShouldProcessSoftErrorCorrectly() {
     $subscribers = [
       'john@doe.com',
       'john@rambo.com',
diff --git a/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php b/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
index fa95a5be03..9ca9db05dc 100644
--- a/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/SendingQueueTest.php
@@ -54,7 +54,7 @@ class SendingQueueTest extends \MailPoetTest {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
@@ -131,13 +131,13 @@ class SendingQueueTest extends \MailPoetTest {
     );
   }
 
-  function testItConstructs() {
+  public function testItConstructs() {
     expect($this->sending_queue_worker->batch_size)->equals(SendingQueueWorker::BATCH_SIZE);
     expect($this->sending_queue_worker->mailer_task instanceof MailerTask);
     expect($this->sending_queue_worker->newsletter_task instanceof NewsletterTask);
   }
 
-  function testItEnforcesExecutionLimitsBeforeQueueProcessing() {
+  public function testItEnforcesExecutionLimitsBeforeQueueProcessing() {
     $sending_queue_worker = Stub::make(
       new SendingQueueWorker(
         $this->sending_error_handler,
@@ -161,7 +161,7 @@ class SendingQueueTest extends \MailPoetTest {
     }
   }
 
-  function testItEnforcesExecutionLimitsAfterSendingWhenQueueStatusIsNotSetToComplete() {
+  public function testItEnforcesExecutionLimitsAfterSendingWhenQueueStatusIsNotSetToComplete() {
     $sending_queue_worker = Stub::make(
       new SendingQueueWorker($this->sending_error_handler, $this->stats_notifications_worker, $this->logger_factory, Stub::makeEmpty(NewslettersRepository::class), $this->cron_helper),
       [
@@ -194,7 +194,7 @@ class SendingQueueTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesNotEnforceExecutionLimitsAfterSendingWhenQueueStatusIsSetToComplete() {
+  public function testItDoesNotEnforceExecutionLimitsAfterSendingWhenQueueStatusIsSetToComplete() {
     // when sending is done and there are no more subscribers to process, continue
     // without enforcing execution limits. this allows the newsletter to be marked as sent
     // in the process() method and after that execution limits will be enforced
@@ -232,7 +232,7 @@ class SendingQueueTest extends \MailPoetTest {
     );
   }
 
-  function testItEnforcesExecutionLimitsAfterQueueProcessing() {
+  public function testItEnforcesExecutionLimitsAfterQueueProcessing() {
     $sending_queue_worker = Stub::make(
       new SendingQueueWorker($this->sending_error_handler, $this->stats_notifications_worker, $this->logger_factory, Stub::makeEmpty(NewslettersRepository::class), $this->cron_helper),
       [
@@ -246,7 +246,7 @@ class SendingQueueTest extends \MailPoetTest {
     $sending_queue_worker->process();
   }
 
-  function testItDeletesQueueWhenNewsletterIsNotFound() {
+  public function testItDeletesQueueWhenNewsletterIsNotFound() {
     // queue exists
     $queue = SendingQueue::findOne($this->queue->id);
     expect($queue)->notEquals(false);
@@ -261,7 +261,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($queue)->false(false);
   }
 
-  function testItPassesExtraParametersToMailerWhenTrackingIsDisabled() {
+  public function testItPassesExtraParametersToMailerWhenTrackingIsDisabled() {
     $this->settings->set('tracking.enabled', false);
     $directUnsubscribeURL = $this->getDirectUnsubscribeURL();
     $sending_queue_worker = new SendingQueueWorker(
@@ -291,7 +291,7 @@ class SendingQueueTest extends \MailPoetTest {
     $sending_queue_worker->process();
   }
 
-  function testItPassesExtraParametersToMailerWhenTrackingIsEnabled() {
+  public function testItPassesExtraParametersToMailerWhenTrackingIsEnabled() {
     $this->settings->set('tracking.enabled', true);
     $trackedUnsubscribeURL = $this->getTrackedUnsubscribeURL();
     $sending_queue_worker = new SendingQueueWorker(
@@ -321,7 +321,7 @@ class SendingQueueTest extends \MailPoetTest {
     $sending_queue_worker->process();
   }
 
-  function testItCanProcessSubscribersOneByOne() {
+  public function testItCanProcessSubscribersOneByOne() {
     $sending_queue_worker = new SendingQueueWorker(
       $this->sending_error_handler,
       $this->stats_notifications_worker,
@@ -368,7 +368,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($statistics)->notEquals(false);
   }
 
-  function testItCanProcessSubscribersInBulk() {
+  public function testItCanProcessSubscribersInBulk() {
     $sending_queue_worker = new SendingQueueWorker(
       $this->sending_error_handler,
       $this->stats_notifications_worker,
@@ -418,7 +418,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($statistics)->notEquals(false);
   }
 
-  function testItProcessesStandardNewsletters() {
+  public function testItProcessesStandardNewsletters() {
     $sending_queue_worker = new SendingQueueWorker(
       $this->sending_error_handler,
       $this->stats_notifications_worker,
@@ -466,7 +466,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($statistics)->notEquals(false);
   }
 
-  function testItUpdatesUpdateTime() {
+  public function testItUpdatesUpdateTime() {
     $originalUpdated = Carbon::createFromTimestamp(current_time('timestamp'))->subHours(5)->toDateTimeString();
 
     $this->queue->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'));
@@ -490,7 +490,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($newQueue->updated_at)->notEquals($originalUpdated);
   }
 
-  function testItCanProcessWelcomeNewsletters() {
+  public function testItCanProcessWelcomeNewsletters() {
     $this->newsletter->type = Newsletter::TYPE_WELCOME;
     $this->newsletter_segment->delete();
 
@@ -540,7 +540,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($statistics)->notEquals(false);
   }
 
-  function testItPreventsSendingWelcomeEmailWhenSubscriberIsUnsubscribed() {
+  public function testItPreventsSendingWelcomeEmailWhenSubscriberIsUnsubscribed() {
     $this->newsletter->type = Newsletter::TYPE_WELCOME;
     $this->subscriber->status = Subscriber::STATUS_UNSUBSCRIBED;
     $this->subscriber->save();
@@ -572,7 +572,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($updated_queue->count_to_process)->equals(0);
   }
 
-  function testItRemovesNonexistentSubscribersFromProcessingList() {
+  public function testItRemovesNonexistentSubscribersFromProcessingList() {
     $queue = $this->queue;
     $queue->setSubscribers([
       $this->subscriber->id(),
@@ -607,7 +607,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect(count($statistics))->equals(1);
   }
 
-  function testItUpdatesQueueSubscriberCountWhenNoneOfSubscribersExist() {
+  public function testItUpdatesQueueSubscriberCountWhenNoneOfSubscribersExist() {
     $queue = $this->queue;
     $queue->setSubscribers([
       123,
@@ -633,7 +633,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($updated_queue->count_to_process)->equals(0);
   }
 
-  function testItDoesNotSendToTrashedSubscribers() {
+  public function testItDoesNotSendToTrashedSubscribers() {
     $sending_queue_worker = $this->sending_queue_worker;
     $sending_queue_worker->mailer_task = Stub::make(
       new MailerTask(),
@@ -656,7 +656,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect((int)$updated_queue->count_total)->equals(0);
   }
 
-  function testItDoesNotSendToGloballyUnsubscribedSubscribers() {
+  public function testItDoesNotSendToGloballyUnsubscribedSubscribers() {
     $sending_queue_worker = $this->sending_queue_worker;
     $sending_queue_worker->mailer_task = Stub::make(
       new MailerTask(),
@@ -672,7 +672,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect((int)$updated_queue->count_total)->equals(0);
   }
 
-  function testItDoesNotSendToSubscribersUnsubscribedFromSegments() {
+  public function testItDoesNotSendToSubscribersUnsubscribedFromSegments() {
     $sending_queue_worker = $this->sending_queue_worker;
     $sending_queue_worker->mailer_task = Stub::make(
       new MailerTask(),
@@ -688,7 +688,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect((int)$updated_queue->count_total)->equals(0);
   }
 
-  function testItDoesNotSendToInactiveSubscribers() {
+  public function testItDoesNotSendToInactiveSubscribers() {
     $sending_queue_worker = $this->sending_queue_worker;
     $sending_queue_worker->mailer_task = Stub::make(
       new MailerTask(),
@@ -704,7 +704,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect((int)$updated_queue->count_total)->equals(0);
   }
 
-  function testItPausesSendingWhenProcessedSubscriberListCannotBeUpdated() {
+  public function testItPausesSendingWhenProcessedSubscriberListCannotBeUpdated() {
     $sending_task = $this->createMock(SendingTask::class);
     $sending_task
       ->method('updateProcessedSubscribers')
@@ -756,7 +756,7 @@ class SendingQueueTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesNotUpdateNewsletterHashDuringSending() {
+  public function testItDoesNotUpdateNewsletterHashDuringSending() {
     $sending_queue_worker = new SendingQueueWorker(
       $this->sending_error_handler,
       $this->stats_notifications_worker,
@@ -779,7 +779,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($updated_newsletter->hash)->equals($this->newsletter->hash);
   }
 
-  function testItAllowsSettingCustomBatchSize() {
+  public function testItAllowsSettingCustomBatchSize() {
     $custom_batch_size_value = 10;
     $filter = function() use ($custom_batch_size_value) {
       return $custom_batch_size_value;
@@ -797,7 +797,7 @@ class SendingQueueTest extends \MailPoetTest {
     $wp->removeFilter('mailpoet_cron_worker_sending_queue_batch_size', $filter);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
diff --git a/tests/integration/Cron/Workers/SendingQueue/Tasks/LinksTest.php b/tests/integration/Cron/Workers/SendingQueue/Tasks/LinksTest.php
index 0398c1b70e..e8e0552b75 100644
--- a/tests/integration/Cron/Workers/SendingQueue/Tasks/LinksTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/Tasks/LinksTest.php
@@ -8,7 +8,7 @@ use MailPoet\Models\NewsletterLink;
 use MailPoetVendor\Idiorm\ORM;
 
 class LinksTest extends \MailPoetTest {
-  function testItCanSaveLinks() {
+  public function testItCanSaveLinks() {
     $links = [
       [
         'link' => 'http://example.com',
@@ -25,7 +25,7 @@ class LinksTest extends \MailPoetTest {
     expect($newsletter_link->url)->equals($links[0]['link']);
   }
 
-  function testItCanHashAndReplaceLinks() {
+  public function testItCanHashAndReplaceLinks() {
     $rendered_newsletter = [
       'html' => '<a href="http://example.com">Example Link</a>',
       'text' => '<a href="http://example.com">Example Link</a>',
@@ -40,7 +40,7 @@ class LinksTest extends \MailPoetTest {
     expect($processed_and_hashed_links[0]['link'])->equals('http://example.com');
   }
 
-  function testItCanProcessRenderedBody() {
+  public function testItCanProcessRenderedBody() {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_STANDARD;
     $newsletter->save();
@@ -55,7 +55,7 @@ class LinksTest extends \MailPoetTest {
     expect($result['html'])->contains($newsletter_link->hash);
   }
 
-  function testItCanEnsureThatUnsubscribeLinkIsAlwaysPresent() {
+  public function testItCanEnsureThatUnsubscribeLinkIsAlwaysPresent() {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_STANDARD;
     $newsletter->save();
@@ -70,7 +70,7 @@ class LinksTest extends \MailPoetTest {
     expect($unsubscribe_count)->equals(1);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterLink::$_table);
   }
diff --git a/tests/integration/Cron/Workers/SendingQueue/Tasks/MailerTest.php b/tests/integration/Cron/Workers/SendingQueue/Tasks/MailerTest.php
index db7da04507..ace8c2ef23 100644
--- a/tests/integration/Cron/Workers/SendingQueue/Tasks/MailerTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/Tasks/MailerTest.php
@@ -23,7 +23,7 @@ class MailerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
@@ -36,11 +36,11 @@ class MailerTest extends \MailPoetTest {
     $this->sender = $this->settings->get('sender');
   }
 
-  function testConfiguresMailerWhenItConstructs() {
+  public function testConfiguresMailerWhenItConstructs() {
     expect($this->mailer_task->mailer instanceof \MailPoet\Mailer\Mailer)->true();
   }
 
-  function testItCanConfigureMailerWithSenderAndReplyToAddresses() {
+  public function testItCanConfigureMailerWithSenderAndReplyToAddresses() {
     $newsletter = new \stdClass();
 
     // when no sender/reply-to information is set, use the sender information
@@ -64,19 +64,19 @@ class MailerTest extends \MailPoetTest {
     expect($mailer->reply_to['reply_to_email'])->equals($newsletter->reply_to_address);
   }
 
-  function testItGetsMailerLog() {
+  public function testItGetsMailerLog() {
     $mailer_log = $this->mailer_task->getMailerLog();
     expect(is_array($mailer_log))->true();
   }
 
-  function testItUpdatesMailerLogSentCount() {
+  public function testItUpdatesMailerLogSentCount() {
     $mailer_log = $this->mailer_task->getMailerLog();
     expect($mailer_log['sent'])->equals(0);
     $mailer_log = $this->mailer_task->updateSentCount();
     expect($mailer_log['sent'])->equals(1);
   }
 
-  function testItGetsProcessingMethod() {
+  public function testItGetsProcessingMethod() {
     // when using MailPoet method, newsletters should be processed in bulk
     $this->settings->set(
       Mailer::MAILER_CONFIG_SETTING_NAME,
@@ -99,7 +99,7 @@ class MailerTest extends \MailPoetTest {
     expect($mailer_task->getProcessingMethod())->equals('individual');
   }
 
-  function testItCanPrepareSubscriberForSending() {
+  public function testItCanPrepareSubscriberForSending() {
     $subscriber = Subscriber::create();
     $subscriber->email = 'test@example.com';
     $subscriber->first_name = 'John';
@@ -109,7 +109,7 @@ class MailerTest extends \MailPoetTest {
     expect($prepared_subscriber)->equals('John Doe <test@example.com>');
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     $php_mail_class = 'MailPoet\Mailer\Methods\PHPMail';
     $this->settings->set(
       Mailer::MAILER_CONFIG_SETTING_NAME,
@@ -139,7 +139,7 @@ class MailerTest extends \MailPoetTest {
     expect($mailer_task->send('Newsletter', 'Subscriber'))->true();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
   }
diff --git a/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php b/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
index 50d069c03c..d66338f27a 100644
--- a/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/Tasks/NewsletterTest.php
@@ -43,7 +43,7 @@ class NewsletterTest extends \MailPoetTest {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter_task = new NewsletterTask();
     $this->subscriber = Subscriber::create();
@@ -71,11 +71,11 @@ class NewsletterTest extends \MailPoetTest {
     $this->logger_factory = LoggerFactory::getInstance();
   }
 
-  function testItConstructs() {
+  public function testItConstructs() {
     expect($this->newsletter_task->tracking_enabled)->true();
   }
 
-  function testItDoesNotGetNewsletterWhenStatusIsNotActiveOrSending() {
+  public function testItDoesNotGetNewsletterWhenStatusIsNotActiveOrSending() {
     // draft or any other status return false
     $newsletter = $this->newsletter;
     $newsletter->status = Newsletter::STATUS_DRAFT;
@@ -94,14 +94,14 @@ class NewsletterTest extends \MailPoetTest {
     expect($this->newsletter_task->getNewsletterFromQueue($this->queue))->isInstanceOf('Mailpoet\Models\Newsletter');
   }
 
-  function testItDoesNotGetDeletedNewsletter() {
+  public function testItDoesNotGetDeletedNewsletter() {
     $newsletter = $this->newsletter;
     $newsletter->set_expr('deleted_at', 'NOW()');
     $newsletter->save();
     expect($this->newsletter_task->getNewsletterFromQueue($this->queue))->false();
   }
 
-  function testItDoesNotGetNewsletterWhenParentNewsletterStatusIsNotActiveOrSending() {
+  public function testItDoesNotGetNewsletterWhenParentNewsletterStatusIsNotActiveOrSending() {
     // draft or any other status return false
     $parent_newsletter = $this->parent_newsletter;
     $parent_newsletter->status = Newsletter::STATUS_DRAFT;
@@ -132,7 +132,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($this->newsletter_task->getNewsletterFromQueue($this->queue))->isInstanceOf('Mailpoet\Models\Newsletter');
   }
 
-  function testItDoesNotGetDeletedNewsletterWhenParentNewsletterIsDeleted() {
+  public function testItDoesNotGetDeletedNewsletterWhenParentNewsletterIsDeleted() {
     $parent_newsletter = $this->parent_newsletter;
     $parent_newsletter->set_expr('deleted_at', 'NOW()');
     $parent_newsletter->save();
@@ -143,14 +143,14 @@ class NewsletterTest extends \MailPoetTest {
     expect($this->newsletter_task->getNewsletterFromQueue($this->queue))->false();
   }
 
-  function testItReturnsNewsletterObjectWhenRenderedNewsletterBodyExistsInTheQueue() {
+  public function testItReturnsNewsletterObjectWhenRenderedNewsletterBodyExistsInTheQueue() {
     $queue = $this->queue;
     $queue->newsletter_rendered_body = ['html' => 'test', 'text' => 'test'];
     $result = $this->newsletter_task->preProcessNewsletter($this->newsletter, $queue);
     expect($result instanceof \MailPoet\Models\Newsletter)->true();
   }
 
-  function testItHashesLinksAndInsertsTrackingImageWhenTrackingIsEnabled() {
+  public function testItHashesLinksAndInsertsTrackingImageWhenTrackingIsEnabled() {
     $wp = Stub::make(new WPFunctions, [
       'applyFilters' => asCallable([WPHooksHelper::class, 'applyFilters']),
     ]);
@@ -172,7 +172,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(WPHooksHelper::getFilterApplied($hook_name)[1] instanceof Newsletter)->true();
   }
 
-  function testItDoesNotHashLinksAndInsertTrackingCodeWhenTrackingIsDisabled() {
+  public function testItDoesNotHashLinksAndInsertTrackingCodeWhenTrackingIsDisabled() {
     $wp = Stub::make(new WPFunctions, [
       'applyFilters' => asCallable([WPHooksHelper::class, 'applyFilters']),
     ]);
@@ -195,7 +195,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(WPHooksHelper::getFilterApplied($hook_name)[1] instanceof Newsletter)->true();
   }
 
-  function testItReturnsFalseAndDeletesNewsletterWhenPostNotificationContainsNoPosts() {
+  public function testItReturnsFalseAndDeletesNewsletterWhenPostNotificationContainsNoPosts() {
     $newsletter = $this->newsletter;
 
     $newsletter->type = Newsletter::TYPE_NOTIFICATION_HISTORY;
@@ -211,7 +211,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter)->false();
   }
 
-  function testItSavesNewsletterPosts() {
+  public function testItSavesNewsletterPosts() {
     $this->newsletter->type = Newsletter::TYPE_NOTIFICATION_HISTORY;
     $this->newsletter->parent_id = $this->newsletter->id;
     $posts_task = $this->make(PostsTask::class, [
@@ -226,7 +226,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter_post->post_id)->equals('10');
   }
 
-  function testItUpdatesStatusAndSetsSentAtDateOnlyForStandardAndPostNotificationNewsletters() {
+  public function testItUpdatesStatusAndSetsSentAtDateOnlyForStandardAndPostNotificationNewsletters() {
     $newsletter = $this->newsletter;
     $queue = new \stdClass();
     $queue->processed_at = date('Y-m-d H:i:s');
@@ -258,7 +258,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($updated_newsletter->status)->notEquals(Newsletter::STATUS_SENT);
   }
 
-  function testItDoesNotRenderSubscriberShortcodeInSubjectWhenPreprocessingNewsletter() {
+  public function testItDoesNotRenderSubscriberShortcodeInSubjectWhenPreprocessingNewsletter() {
     $newsletter = $this->newsletter;
     $newsletter->subject = 'Newsletter for [subscriber:firstname] [date:dordinal]';
     $queue = $this->queue;
@@ -269,7 +269,7 @@ class NewsletterTest extends \MailPoetTest {
       ->contains(date_i18n('jS', $wp->currentTime('timestamp')));
   }
 
-  function testItUsesADefaultSubjectIfRenderedSubjectIsEmptyWhenPreprocessingNewsletter() {
+  public function testItUsesADefaultSubjectIfRenderedSubjectIsEmptyWhenPreprocessingNewsletter() {
     $newsletter = $this->newsletter;
     $newsletter->subject = '  [custom_shortcode:should_render_empty]  ';
     $queue = $this->queue;
@@ -279,7 +279,7 @@ class NewsletterTest extends \MailPoetTest {
       ->equals('No subject');
   }
 
-  function testItUsesRenderedNewsletterBodyAndSubjectFromQueueObjectWhenPreparingNewsletterForSending() {
+  public function testItUsesRenderedNewsletterBodyAndSubjectFromQueueObjectWhenPreparingNewsletterForSending() {
     $queue = $this->queue;
     $queue->newsletter_rendered_body = [
       'html' => 'queue HTML body',
@@ -304,7 +304,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($result['body']['text'])->equals('queue TEXT body');
   }
 
-  function testItRendersShortcodesAndReplacesSubscriberDataInLinks() {
+  public function testItRendersShortcodesAndReplacesSubscriberDataInLinks() {
     $newsletter = $this->newsletter_task->preProcessNewsletter($this->newsletter, $this->queue);
     $result = $this->newsletter_task->prepareNewsletterForSending(
       $newsletter,
@@ -318,7 +318,7 @@ class NewsletterTest extends \MailPoetTest {
       ->contains(Router::NAME . '&endpoint=track&action=click&data=');
   }
 
-  function testItDoesNotReplaceSubscriberDataInLinksWhenTrackingIsNotEnabled() {
+  public function testItDoesNotReplaceSubscriberDataInLinksWhenTrackingIsNotEnabled() {
     $newsletter_task = $this->newsletter_task;
     $newsletter_task->tracking_enabled = false;
     $newsletter = $newsletter_task->preProcessNewsletter($this->newsletter, $this->queue);
@@ -333,7 +333,7 @@ class NewsletterTest extends \MailPoetTest {
       ->notContains(Router::NAME . '&endpoint=track&action=click&data=');
   }
 
-  function testItGetsSegments() {
+  public function testItGetsSegments() {
     for ($i = 1; $i <= 3; $i++) {
       $newsletter_segment = NewsletterSegment::create();
       $newsletter_segment->newsletter_id = $this->newsletter->id;
@@ -345,7 +345,7 @@ class NewsletterTest extends \MailPoetTest {
     );
   }
 
-  function testItLogsErrorWhenQueueWithCannotBeSaved() {
+  public function testItLogsErrorWhenQueueWithCannotBeSaved() {
     $queue = $this->queue;
     $queue->non_existent_column = true; // this will trigger save error
     try {
@@ -358,7 +358,7 @@ class NewsletterTest extends \MailPoetTest {
     }
   }
 
-  function testItLogsErrorWhenExistingRenderedNewsletterBodyIsInvalid() {
+  public function testItLogsErrorWhenExistingRenderedNewsletterBodyIsInvalid() {
     $queue_mock = $this->createMock(SendingTask::class);
     $queue_mock
       ->expects($this->any())
@@ -379,7 +379,7 @@ class NewsletterTest extends \MailPoetTest {
     }
   }
 
-  function testItLogsErrorWhenNewlyRenderedNewsletterBodyIsInvalid() {
+  public function testItLogsErrorWhenNewlyRenderedNewsletterBodyIsInvalid() {
     $queue = $this->queue;
     $queue_mock = $this->createMock(SendingTask::class);
     $queue_mock
@@ -410,7 +410,7 @@ class NewsletterTest extends \MailPoetTest {
     }
   }
 
-  function testItPreProcessesNewsletterWhenNewlyRenderedNewsletterBodyIsValid() {
+  public function testItPreProcessesNewsletterWhenNewlyRenderedNewsletterBodyIsValid() {
     $queue = $this->queue;
     $queue_mock = $this->createMock(SendingTask::class);
     $queue_mock
@@ -444,7 +444,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter_task->preProcessNewsletter($this->newsletter, $queue_mock))->equals($this->newsletter);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
diff --git a/tests/integration/Cron/Workers/SendingQueue/Tasks/PostsTest.php b/tests/integration/Cron/Workers/SendingQueue/Tasks/PostsTest.php
index d0f354c0de..e5926e3012 100644
--- a/tests/integration/Cron/Workers/SendingQueue/Tasks/PostsTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/Tasks/PostsTest.php
@@ -12,12 +12,12 @@ class PostsTest extends \MailPoetTest {
   /** @var PostsTask */
   private $posts_task;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->posts_task = new PostsTask;
   }
 
-  function testItFailsWhenNoPostsArePresent() {
+  public function testItFailsWhenNoPostsArePresent() {
     $newsletter = (object)[
       'id' => 1,
       'type' => Newsletter::TYPE_NOTIFICATION_HISTORY,
@@ -28,7 +28,7 @@ class PostsTest extends \MailPoetTest {
     expect($this->posts_task->extractAndSave($rendered_newsletter, $newsletter))->equals(false);
   }
 
-  function testItCanExtractAndSavePosts() {
+  public function testItCanExtractAndSavePosts() {
     $post_id = 10;
     $newsletter = (object)[
       'id' => 2,
@@ -44,7 +44,7 @@ class PostsTest extends \MailPoetTest {
     expect($newsletter_post->post_id)->equals($post_id);
   }
 
-  function testItDoesNotSavePostsWhenNewsletterIsNotANotificationHistory() {
+  public function testItDoesNotSavePostsWhenNewsletterIsNotANotificationHistory() {
     $post_id = 10;
     $newsletter = (object)[
       'id' => 2,
@@ -59,7 +59,7 @@ class PostsTest extends \MailPoetTest {
     expect($this->posts_task->extractAndSave($rendered_newsletter, $newsletter))->equals(false);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . NewsletterPost::$_table);
   }
 }
diff --git a/tests/integration/Cron/Workers/SendingQueue/Tasks/ShortcodesTest.php b/tests/integration/Cron/Workers/SendingQueue/Tasks/ShortcodesTest.php
index 7692915758..f53c43bce3 100644
--- a/tests/integration/Cron/Workers/SendingQueue/Tasks/ShortcodesTest.php
+++ b/tests/integration/Cron/Workers/SendingQueue/Tasks/ShortcodesTest.php
@@ -9,7 +9,7 @@ use MailPoet\Models\Subscriber;
 use MailPoetVendor\Idiorm\ORM;
 
 class ShortcodesTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->WP_post = wp_insert_post(
       [
@@ -20,7 +20,7 @@ class ShortcodesTest extends \MailPoetTest {
     );
   }
 
-  function testItCanReplaceShortcodes() {
+  public function testItCanReplaceShortcodes() {
     $queue = $newsletter = (object)[
       'id' => 1,
     ];
@@ -35,7 +35,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result)->equals('John Doe');
   }
 
-  function testItCanReplaceShortcodesInOneStringUsingContentsFromAnother() {
+  public function testItCanReplaceShortcodesInOneStringUsingContentsFromAnother() {
     $wp_post = get_post($this->WP_post);
     $content = 'Subject line with one shortcode: [newsletter:post_title]';
     $content_source = '<a data-post-id="' . $this->WP_post . '" href="#">latest post</a>';
@@ -48,7 +48,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect(Shortcodes::process($content, $content_source))->equals('Subject line with one shortcode: ' . $wp_post->post_title);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     wp_delete_post($this->WP_post, true);
diff --git a/tests/integration/Cron/Workers/SimpleWorkerMockImplementation.php b/tests/integration/Cron/Workers/SimpleWorkerMockImplementation.php
index 13510ef954..0acb4ee947 100644
--- a/tests/integration/Cron/Workers/SimpleWorkerMockImplementation.php
+++ b/tests/integration/Cron/Workers/SimpleWorkerMockImplementation.php
@@ -6,7 +6,7 @@ class SimpleWorkerMockImplementation extends SimpleWorker {
   const TASK_TYPE = 'mock_simple_worker';
   const SUPPORT_MULTIPLE_INSTANCES = false;
 
-  function init() {
+  public function init() {
     // to be mocked
   }
 }
diff --git a/tests/integration/Cron/Workers/SimpleWorkerTest.php b/tests/integration/Cron/Workers/SimpleWorkerTest.php
index caf98976c1..94ae425bb9 100644
--- a/tests/integration/Cron/Workers/SimpleWorkerTest.php
+++ b/tests/integration/Cron/Workers/SimpleWorkerTest.php
@@ -14,13 +14,13 @@ use MailPoetVendor\Idiorm\ORM;
 require_once __DIR__ . '/SimpleWorkerMockImplementation.php';
 
 class SimpleWorkerTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cron_helper = ContainerWrapper::getInstance()->get(CronHelper::class);
     $this->worker = new MockSimpleWorker();
   }
 
-  function testItRequiresTaskTypeToConstruct() {
+  public function testItRequiresTaskTypeToConstruct() {
     $worker = Stub::make(
       'MailPoet\Cron\Workers\SimpleWorker',
       [],
@@ -35,13 +35,13 @@ class SimpleWorkerTest extends \MailPoetTest {
     }
   }
 
-  function testItSchedulesTask() {
+  public function testItSchedulesTask() {
     expect(ScheduledTask::where('type', MockSimpleWorker::TASK_TYPE)->findMany())->isEmpty();
     (new MockSimpleWorker())->schedule();
     expect(ScheduledTask::where('type', MockSimpleWorker::TASK_TYPE)->findMany())->notEmpty();
   }
 
-  function testItDoesNotScheduleTaskTwice() {
+  public function testItDoesNotScheduleTaskTwice() {
     $worker = new MockSimpleWorker();
     expect(count(ScheduledTask::where('type', MockSimpleWorker::TASK_TYPE)->findMany()))->equals(0);
     $worker->schedule();
@@ -50,7 +50,7 @@ class SimpleWorkerTest extends \MailPoetTest {
     expect(count(ScheduledTask::where('type', MockSimpleWorker::TASK_TYPE)->findMany()))->equals(1);
   }
 
-  function testItCalculatesNextRunDateWithinNextWeekBoundaries() {
+  public function testItCalculatesNextRunDateWithinNextWeekBoundaries() {
     $current_date = Carbon::createFromTimestamp(current_time('timestamp'));
     $next_run_date = (new MockSimpleWorker())->getNextRunDate();
     $difference = $next_run_date->diffInDays($current_date);
@@ -60,7 +60,7 @@ class SimpleWorkerTest extends \MailPoetTest {
     expect($difference)->greaterOrEquals(0);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
diff --git a/tests/integration/Cron/Workers/StatsNotifications/AutomatedEmailsTest.php b/tests/integration/Cron/Workers/StatsNotifications/AutomatedEmailsTest.php
index 24ee8987ed..da1d115110 100644
--- a/tests/integration/Cron/Workers/StatsNotifications/AutomatedEmailsTest.php
+++ b/tests/integration/Cron/Workers/StatsNotifications/AutomatedEmailsTest.php
@@ -36,7 +36,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
   /** @var CronWorkerRunner */
   private $cron_worker_runner;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
@@ -68,7 +68,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     $this->settings->set('tracking.enabled', true);
   }
 
-  function testItDoesntWorkIfDisabled() {
+  public function testItDoesntWorkIfDisabled() {
     $this->settings->set(Worker::SETTINGS_KEY, [
       'automated' => false,
       'address' => 'email@example.com',
@@ -76,7 +76,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     expect($this->stats_notifications->checkProcessingRequirements())->equals(false);
   }
 
-  function testItDoesntWorkIfNoEmail() {
+  public function testItDoesntWorkIfNoEmail() {
     $this->settings->set(Worker::SETTINGS_KEY, [
       'automated' => true,
       'address' => '',
@@ -84,16 +84,16 @@ class AutomatedEmailsTest extends \MailPoetTest {
     expect($this->stats_notifications->checkProcessingRequirements())->equals(false);
   }
 
-  function testItDoesntWorkIfTrackingIsDisabled() {
+  public function testItDoesntWorkIfTrackingIsDisabled() {
     $this->settings->set('tracking.enabled', false);
     expect($this->stats_notifications->checkProcessingRequirements())->equals(false);
   }
 
-  function testItDoesWorkIfEnabled() {
+  public function testItDoesWorkIfEnabled() {
     expect($this->stats_notifications->checkProcessingRequirements())->equals(true);
   }
 
-  function testItDoesntRenderIfNoNewslettersFound() {
+  public function testItDoesntRenderIfNoNewslettersFound() {
     $this->renderer->expects($this->never())
       ->method('render');
     $this->mailer->expects($this->never())
@@ -104,7 +104,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     expect($result)->equals(true);
   }
 
-  function testItRenders() {
+  public function testItRenders() {
     Newsletter::createOrUpdate([
       'id' => 8763,
       'subject' => 'Subject',
@@ -132,7 +132,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     expect($result)->equals(true);
   }
 
-  function testItSends() {
+  public function testItSends() {
     Newsletter::createOrUpdate([
       'id' => 8763,
       'subject' => 'Subject',
@@ -162,7 +162,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     expect($result)->equals(true);
   }
 
-  function testItPreparesContext() {
+  public function testItPreparesContext() {
     Newsletter::createOrUpdate([
       'id' => 8764,
       'subject' => 'Subject',
@@ -183,7 +183,7 @@ class AutomatedEmailsTest extends \MailPoetTest {
     $this->cron_worker_runner->run($this->stats_notifications);
   }
 
-  function testItAddsNewsletterStatsToContext() {
+  public function testItAddsNewsletterStatsToContext() {
     Newsletter::createOrUpdate([
       'id' => 8765,
       'subject' => 'Subject',
diff --git a/tests/integration/Cron/Workers/StatsNotifications/WorkerTest.php b/tests/integration/Cron/Workers/StatsNotifications/WorkerTest.php
index c6a09027ea..52d526cd6b 100644
--- a/tests/integration/Cron/Workers/StatsNotifications/WorkerTest.php
+++ b/tests/integration/Cron/Workers/StatsNotifications/WorkerTest.php
@@ -51,7 +51,7 @@ class WorkerTest extends \MailPoetTest {
   /** @var NewsletterLinkRepository */
   private $newsletter_link_repository;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . StatisticsClicks::$_table);
@@ -164,7 +164,7 @@ class WorkerTest extends \MailPoetTest {
     ]);
   }
 
-  function testRendersTemplate() {
+  public function testRendersTemplate() {
     $this->renderer->expects($this->exactly(2))
        ->method('render');
     $this->renderer->expects($this->at(0))
@@ -178,7 +178,7 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testAddsSubjectToContext() {
+  public function testAddsSubjectToContext() {
     $this->renderer->expects($this->exactly(2)) // html + text template
      ->method('render')
      ->with(
@@ -190,7 +190,7 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testAddsPreHeaderToContext() {
+  public function testAddsPreHeaderToContext() {
     $this->renderer->expects($this->exactly(2)) // html + text template
       ->method('render')
       ->with(
@@ -202,7 +202,7 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testAddsWPUrlsToContext() {
+  public function testAddsWPUrlsToContext() {
     $this->renderer->expects($this->exactly(2)) // html + text template
       ->method('render')
       ->with(
@@ -215,7 +215,7 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testAddsLinksToContext() {
+  public function testAddsLinksToContext() {
     $this->renderer->expects($this->exactly(2)) // html + text template
       ->method('render')
       ->with(
@@ -228,7 +228,7 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testReplacesShortcodeLinks() {
+  public function testReplacesShortcodeLinks() {
     $link = NewsletterLink::createOrUpdate([
       'url' => '[link:subscription_manage_url]',
       'newsletter_id' => $this->newsletter->id(),
@@ -270,14 +270,14 @@ class WorkerTest extends \MailPoetTest {
     $this->stats_notifications->process();
   }
 
-  function testSends() {
+  public function testSends() {
     $this->mailer->expects($this->once())
       ->method('send');
 
     $this->stats_notifications->process();
   }
 
-  function testItWorksForNewsletterWithNoStats() {
+  public function testItWorksForNewsletterWithNoStats() {
     $newsletter = Newsletter::createOrUpdate([
       'subject' => 'Email Subject2',
       'type' => Newsletter::TYPE_STANDARD,
diff --git a/tests/integration/Cron/Workers/UnsubscribeTokensTest.php b/tests/integration/Cron/Workers/UnsubscribeTokensTest.php
index 35a0ff0314..d1b4f8e8df 100644
--- a/tests/integration/Cron/Workers/UnsubscribeTokensTest.php
+++ b/tests/integration/Cron/Workers/UnsubscribeTokensTest.php
@@ -17,7 +17,7 @@ class UnsubscribeTokensTest extends \MailPoetTest {
   private $subscriber_without_token;
   private $newsletter_without_token;
 
-  function _before() {
+  public function _before() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
@@ -47,7 +47,7 @@ class UnsubscribeTokensTest extends \MailPoetTest {
     $this->newsletter_without_token->save();
   }
 
-  function testItAddsTokensToSubscribers() {
+  public function testItAddsTokensToSubscribers() {
     $worker = new UnsubscribeTokens();
     $worker->processTaskStrategy(ScheduledTask::createOrUpdate(), microtime(true));
     $this->subscriber_with_token = Subscriber::findOne($this->subscriber_with_token->id);
@@ -56,7 +56,7 @@ class UnsubscribeTokensTest extends \MailPoetTest {
     expect(strlen($this->subscriber_without_token->unsubscribe_token))->equals(15);
   }
 
-  function testItAddsTokensToNewsletters() {
+  public function testItAddsTokensToNewsletters() {
     $worker = new UnsubscribeTokens();
     $worker->processTaskStrategy(ScheduledTask::createOrUpdate(), microtime(true));
     $this->newsletter_with_token = Newsletter::findOne($this->newsletter_with_token->id);
@@ -65,7 +65,7 @@ class UnsubscribeTokensTest extends \MailPoetTest {
     expect(strlen($this->newsletter_without_token->unsubscribe_token))->equals(15);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
diff --git a/tests/integration/Cron/Workers/WooCommerceOrdersTest.php b/tests/integration/Cron/Workers/WooCommerceOrdersTest.php
index f4f6c86fdf..b3b6c2531d 100644
--- a/tests/integration/Cron/Workers/WooCommerceOrdersTest.php
+++ b/tests/integration/Cron/Workers/WooCommerceOrdersTest.php
@@ -26,7 +26,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
   /** @var CronWorkerRunner */
   private $cron_worker_runner;
 
-  function _before() {
+  public function _before() {
     $this->cleanup();
     $this->woocommerce_helper = $this->createMock(WooCommerceHelper::class);
     $this->woocommerce_purchases = $this->createMock(WooCommercePurchases::class);
@@ -37,7 +37,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     ]);
   }
 
-  function testItDoesNotRunIfWooCommerceIsDisabled() {
+  public function testItDoesNotRunIfWooCommerceIsDisabled() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(false);
     expect($this->worker->checkProcessingRequirements())->false();
 
@@ -46,7 +46,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     expect($tasks)->isEmpty();
   }
 
-  function testItRunsIfWooCommerceIsEnabled() {
+  public function testItRunsIfWooCommerceIsEnabled() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     expect($this->worker->checkProcessingRequirements())->true();
 
@@ -55,7 +55,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function testItRunsOnlyOnce() {
+  public function testItRunsOnlyOnce() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     $this->woocommerce_helper->method('wcGetOrders')->willReturn([]);
 
@@ -87,7 +87,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function testItTracksOrders() {
+  public function testItTracksOrders() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     $this->woocommerce_helper->method('wcGetOrders')->willReturn([1, 2, 3]);
     $this->createClick();
@@ -104,7 +104,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
   }
 
 
-  function testItContinuesFromLastId() {
+  public function testItContinuesFromLastId() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     $this->woocommerce_helper->method('wcGetOrders')->willReturnOnConsecutiveCalls([1, 2, 3], [4, 5], []);
     $this->createClick();
@@ -130,7 +130,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     expect($tasks[0]->status)->equals(ScheduledTask::STATUS_COMPLETED);
   }
 
-  function testItResetsPreviouslyTrackedOrders() {
+  public function testItResetsPreviouslyTrackedOrders() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     $this->woocommerce_helper->method('wcGetOrders')->willReturnOnConsecutiveCalls([1, 2], [3], [4]);
     $click = $this->createClick();
@@ -159,7 +159,7 @@ class WooCommerceOrdersTest extends \MailPoetTest {
     expect(StatisticsWooCommercePurchases::findMany())->count(0);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanup();
   }
 
diff --git a/tests/integration/Cron/Workers/WooCommerceSyncTest.php b/tests/integration/Cron/Workers/WooCommerceSyncTest.php
index c01a734983..74c0e441f3 100644
--- a/tests/integration/Cron/Workers/WooCommerceSyncTest.php
+++ b/tests/integration/Cron/Workers/WooCommerceSyncTest.php
@@ -10,25 +10,25 @@ use MailPoetVendor\Carbon\Carbon;
 use MailPoetVendor\Idiorm\ORM;
 
 class WooCommerceSyncTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     $this->woocommerce_segment = $this->createMock(WooCommerceSegment::class);
     $this->woocommerce_helper = $this->createMock(WooCommerceHelper::class);
     $this->worker = new WooCommerceSync($this->woocommerce_segment, $this->woocommerce_helper, microtime(true));
   }
 
-  function testItWillNotRunIfWooCommerceIsDisabled() {
+  public function testItWillNotRunIfWooCommerceIsDisabled() {
     $this->woocommerce_helper->method('isWooCommerceActive')
       ->willReturn(false);
     expect($this->worker->checkProcessingRequirements())->false();
   }
 
-  function testItWillRunIfWooCommerceIsEnabled() {
+  public function testItWillRunIfWooCommerceIsEnabled() {
     $this->woocommerce_helper->method('isWooCommerceActive')
       ->willReturn(true);
     expect($this->worker->checkProcessingRequirements())->true();
   }
 
-  function testItCallsWooCommerceSync() {
+  public function testItCallsWooCommerceSync() {
     $this->woocommerce_segment->expects($this->once())
       ->method('synchronizeCustomers');
     $task = $this->createScheduledTask();
@@ -44,7 +44,7 @@ class WooCommerceSyncTest extends \MailPoetTest {
     return $task;
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
   }
 }
diff --git a/tests/integration/Doctrine/ConfigurationFactoryTest.php b/tests/integration/Doctrine/ConfigurationFactoryTest.php
index 65353a8072..bd3607a8f7 100644
--- a/tests/integration/Doctrine/ConfigurationFactoryTest.php
+++ b/tests/integration/Doctrine/ConfigurationFactoryTest.php
@@ -13,7 +13,7 @@ use MailPoetVendor\Doctrine\ORM\Mapping\Driver\AnnotationDriver;
 use MailPoetVendor\Doctrine\ORM\Mapping\UnderscoreNamingStrategy;
 
 class ConfigurationFactoryTest extends \MailPoetTest {
-  function testItSetsUpBasicOptions() {
+  public function testItSetsUpBasicOptions() {
     $configuration_factory = new ConfigurationFactory(false, new AnnotationReaderProvider());
     $configuration = $configuration_factory->createConfiguration();
 
@@ -34,7 +34,7 @@ class ConfigurationFactoryTest extends \MailPoetTest {
     expect($configuration->getProxyNamespace())->equals('MailPoetDoctrineProxies');
   }
 
-  function testItSetsUpEnvironmentSpecificOptions() {
+  public function testItSetsUpEnvironmentSpecificOptions() {
     // dev mode
     $configuration_factory = new ConfigurationFactory(true, new AnnotationReaderProvider());
     $configuration = $configuration_factory->createConfiguration();
diff --git a/tests/integration/Doctrine/ConnectionFactoryTest.php b/tests/integration/Doctrine/ConnectionFactoryTest.php
index c5ae3b3cd0..c3df5ab625 100644
--- a/tests/integration/Doctrine/ConnectionFactoryTest.php
+++ b/tests/integration/Doctrine/ConnectionFactoryTest.php
@@ -15,7 +15,7 @@ use PDO;
 class ConnectionFactoryTest extends \MailPoetTest {
   private $env_backup = [];
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->env_backup['db_host'] = Env::$db_host;
     $this->env_backup['db_is_ipv6'] = Env::$db_is_ipv6;
@@ -24,7 +24,7 @@ class ConnectionFactoryTest extends \MailPoetTest {
     $this->env_backup['db_charset'] = Env::$db_charset;
   }
 
-  function testItSetsUpConnection() {
+  public function testItSetsUpConnection() {
     $connection_factory = new ConnectionFactory();
     $connection = $connection_factory->createConnection();
 
@@ -44,14 +44,14 @@ class ConnectionFactoryTest extends \MailPoetTest {
     expect(Type::getType(JsonOrSerializedType::NAME))->isInstanceOf(JsonOrSerializedType::class);
   }
 
-  function testItIgnoresEmptyCharset() {
+  public function testItIgnoresEmptyCharset() {
     Env::$db_charset = '';
     $connection_factory = new ConnectionFactory();
     $connection = $connection_factory->createConnection();
     expect($connection->getParams())->hasntKey('charset');
   }
 
-  function testItSetsUpSocket() {
+  public function testItSetsUpSocket() {
     Env::$db_host = null;
     Env::$db_port = null;
     Env::$db_socket = 'socket';
@@ -63,7 +63,7 @@ class ConnectionFactoryTest extends \MailPoetTest {
     expect($connection->getParams()['unix_socket'])->equals('socket');
   }
 
-  function testItSetsUpIpV6() {
+  public function testItSetsUpIpV6() {
     Env::$db_is_ipv6 = true;
 
     Env::$db_host = '::1';
@@ -84,7 +84,7 @@ class ConnectionFactoryTest extends \MailPoetTest {
     expect($connection->executeQuery('SELECT 1')->fetchColumn())->same('1');
   }
 
-  function testItSetsDriverOptions() {
+  public function testItSetsDriverOptions() {
     $connection_factory = new ConnectionFactory();
     $connection = $connection_factory->createConnection();
 
@@ -111,7 +111,7 @@ class ConnectionFactoryTest extends \MailPoetTest {
     expect($result['@@session.collation_connection'])->equals(Env::$db_collation);
   }
 
-  function testItSelectivelyUpdatesWaitTimeoutOption() {
+  public function testItSelectivelyUpdatesWaitTimeoutOption() {
     // timeout will be kept from DB defaults
     $connection_factory = $this->make(ConnectionFactory::class, [
       'min_wait_timeout' => 1,
@@ -129,7 +129,7 @@ class ConnectionFactoryTest extends \MailPoetTest {
     expect($current)->equals(999999);
   }
 
-  function _after() {
+  public function _after() {
     parent::_after();
     Env::$db_host = $this->env_backup['db_host'];
     Env::$db_port = $this->env_backup['db_port'];
diff --git a/tests/integration/Doctrine/EventListeners/TimestampEntity.php b/tests/integration/Doctrine/EventListeners/TimestampEntity.php
index f838ff18a7..27b7a2166e 100644
--- a/tests/integration/Doctrine/EventListeners/TimestampEntity.php
+++ b/tests/integration/Doctrine/EventListeners/TimestampEntity.php
@@ -29,17 +29,17 @@ class TimestampEntity {
   private $name;
 
   /** @return int|null */
-  function getId() {
+  public function getId() {
     return $this->id;
   }
 
   /** @return string */
-  function getName() {
+  public function getName() {
     return $this->name;
   }
 
   /** @param string $name */
-  function setName($name) {
+  public function setName($name) {
     $this->name = $name;
   }
 }
diff --git a/tests/integration/Doctrine/EventListeners/TimestampListenerTest.php b/tests/integration/Doctrine/EventListeners/TimestampListenerTest.php
index dcaa9d213f..a4afbf9ab2 100644
--- a/tests/integration/Doctrine/EventListeners/TimestampListenerTest.php
+++ b/tests/integration/Doctrine/EventListeners/TimestampListenerTest.php
@@ -24,7 +24,7 @@ class TimestampListenerTest extends \MailPoetTest {
   /** @var string */
   private $table_name;
 
-  function _before() {
+  public function _before() {
     $timestamp = time();
     $this->now = Carbon::createFromTimestamp($timestamp);
     $this->wp = $this->make(WPFunctions::class, [
@@ -44,7 +44,7 @@ class TimestampListenerTest extends \MailPoetTest {
     ");
   }
 
-  function testItSetsTimestampsOnCreate() {
+  public function testItSetsTimestampsOnCreate() {
     $entity = new TimestampEntity();
     $entity->setName('Created');
 
@@ -55,7 +55,7 @@ class TimestampListenerTest extends \MailPoetTest {
     expect($entity->getUpdatedAt())->equals($this->now);
   }
 
-  function testItSetsTimestampOnUpdate() {
+  public function testItSetsTimestampOnUpdate() {
     $this->connection->executeUpdate("
       INSERT INTO $this->table_name (id, created_at, updated_at, name) VALUES (
         123,
@@ -73,7 +73,7 @@ class TimestampListenerTest extends \MailPoetTest {
     expect($entity->getUpdatedAt())->equals($this->now);
   }
 
-  function _after() {
+  public function _after() {
     parent::_after();
     $this->connection->executeUpdate("DROP TABLE IF EXISTS $this->table_name");
   }
diff --git a/tests/integration/Doctrine/EventListeners/ValidatedEntity.php b/tests/integration/Doctrine/EventListeners/ValidatedEntity.php
index 3eaa6a92a8..940ed0c140 100644
--- a/tests/integration/Doctrine/EventListeners/ValidatedEntity.php
+++ b/tests/integration/Doctrine/EventListeners/ValidatedEntity.php
@@ -27,7 +27,7 @@ class ValidatedEntity {
   private $name;
 
   /** @return int */
-  function getId() {
+  public function getId() {
     return $this->id;
   }
 
diff --git a/tests/integration/Doctrine/EventListeners/ValidationTest.php b/tests/integration/Doctrine/EventListeners/ValidationTest.php
index d4d13ffd8d..edc1791d4e 100644
--- a/tests/integration/Doctrine/EventListeners/ValidationTest.php
+++ b/tests/integration/Doctrine/EventListeners/ValidationTest.php
@@ -21,7 +21,7 @@ class ValidationTest extends \MailPoetTest {
   /** @var string */
   private $table_name;
 
-  function _before() {
+  public function _before() {
     $this->wp = new WPFunctions();
     $this->entity_manager = $this->createEntityManager();
     $this->table_name = $this->entity_manager->getClassMetadata(ValidatedEntity::class)->getTableName();
@@ -34,7 +34,7 @@ class ValidationTest extends \MailPoetTest {
     ");
   }
 
-  function testItValidatesNewEntity() {
+  public function testItValidatesNewEntity() {
     $entity = new ValidatedEntity();
     $this->entity_manager->persist($entity);
     try {
@@ -46,7 +46,7 @@ class ValidationTest extends \MailPoetTest {
     }
   }
 
-  function testItValidatesUpdatedEntity() {
+  public function testItValidatesUpdatedEntity() {
     $id = 1;
     $name = 'Test name';
     $this->connection->executeUpdate("INSERT INTO $this->table_name (id, name) VALUES (?, ?)", [$id, $name]);
diff --git a/tests/integration/Doctrine/Types/JsonEntity.php b/tests/integration/Doctrine/Types/JsonEntity.php
index f94a784751..044be5ef6b 100644
--- a/tests/integration/Doctrine/Types/JsonEntity.php
+++ b/tests/integration/Doctrine/Types/JsonEntity.php
@@ -32,7 +32,7 @@ class JsonEntity {
   /**
    * @return int|null
    */
-  function getId() {
+  public function getId() {
     return $this->id;
   }
 
diff --git a/tests/integration/Doctrine/Types/JsonTypesTest.php b/tests/integration/Doctrine/Types/JsonTypesTest.php
index 3721789bcd..93cd564bfc 100644
--- a/tests/integration/Doctrine/Types/JsonTypesTest.php
+++ b/tests/integration/Doctrine/Types/JsonTypesTest.php
@@ -33,7 +33,7 @@ class JsonTypesTest extends \MailPoetTest {
     ],
   ];
 
-  function _before() {
+  public function _before() {
     $this->wp = new WPFunctions();
     $this->entity_manager = $this->createEntityManager();
     $this->table_name = $this->entity_manager->getClassMetadata(JsonEntity::class)->getTableName();
@@ -47,7 +47,7 @@ class JsonTypesTest extends \MailPoetTest {
     ");
   }
 
-  function testItSavesJsonData() {
+  public function testItSavesJsonData() {
     $entity = new JsonEntity();
     $entity->setJsonData($this->test_data);
     $entity->setJsonOrSerializedData($this->test_data);
@@ -59,7 +59,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($saved_data['json_or_serialized_data'])->same(json_encode($this->test_data));
   }
 
-  function testItLoadsJsonData() {
+  public function testItLoadsJsonData() {
     $this->connection->executeUpdate(
       "INSERT INTO $this->table_name (id, json_data, json_or_serialized_data) VALUES (?, ?, ?)",
       [
@@ -74,7 +74,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($entity->getJsonOrSerializedData())->same($this->test_data);
   }
 
-  function testItLoadsSerializedData() {
+  public function testItLoadsSerializedData() {
     $this->connection->executeUpdate(
       "INSERT INTO $this->table_name (id, json_or_serialized_data) VALUES (?, ?)",
       [
@@ -88,7 +88,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($entity->getJsonOrSerializedData())->same($this->test_data);
   }
 
-  function testItSavesNullData() {
+  public function testItSavesNullData() {
     $entity = new JsonEntity();
     $entity->setJsonData(null);
     $entity->setJsonOrSerializedData(null);
@@ -100,7 +100,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($saved_data['json_or_serialized_data'])->null();
   }
 
-  function testItLoadsNullData() {
+  public function testItLoadsNullData() {
     $this->connection->executeUpdate(
       "INSERT INTO $this->table_name (id, json_data, json_or_serialized_data) VALUES (?, ?, ?)",
       [
@@ -115,7 +115,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($entity->getJsonOrSerializedData())->null();
   }
 
-  function testItLoadsEmptyStringAsNull() {
+  public function testItLoadsEmptyStringAsNull() {
     $this->connection->executeUpdate(
       "INSERT INTO $this->table_name (id, json_data, json_or_serialized_data) VALUES (?, ?, ?)",
       [
@@ -130,7 +130,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($entity->getJsonOrSerializedData())->null();
   }
 
-  function testItDoesNotSaveInvalidData() {
+  public function testItDoesNotSaveInvalidData() {
     $entity = new JsonEntity();
     $entity->setJsonData("\xB1\x31"); // invalid unicode sequence
     $this->entity_manager->persist($entity);
@@ -144,7 +144,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($exception)->isInstanceOf(RuntimeException::class);
   }
 
-  function testItDoesNotLoadInvalidData() {
+  public function testItDoesNotLoadInvalidData() {
     $this->connection->executeUpdate(
       "INSERT INTO $this->table_name (id, json_data) VALUES (?, ?)",
       [
@@ -162,7 +162,7 @@ class JsonTypesTest extends \MailPoetTest {
     expect($exception)->isInstanceOf(RuntimeException::class);
   }
 
-  function _after() {
+  public function _after() {
     parent::_after();
     $this->connection->executeUpdate("DROP TABLE IF EXISTS $this->table_name");
   }
diff --git a/tests/integration/DynamicSegments/Filters/EmailActionTest.php b/tests/integration/DynamicSegments/Filters/EmailActionTest.php
index 85319395b3..1868abc707 100644
--- a/tests/integration/DynamicSegments/Filters/EmailActionTest.php
+++ b/tests/integration/DynamicSegments/Filters/EmailActionTest.php
@@ -10,7 +10,7 @@ use MailPoet\Models\Subscriber;
 
 class EmailActionTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     $this->newsletter = Newsletter::createOrUpdate([
       'subject' => 'newsletter 1',
       'status' => 'sent',
@@ -38,55 +38,55 @@ class EmailActionTest extends \MailPoetTest {
     StatisticsClicks::createOrUpdateClickCount(1, $this->subscriber_opened_clicked->id, $this->newsletter->id, 1);
   }
 
-  function testGetOpened() {
+  public function testGetOpened() {
     $emailAction = new EmailAction(EmailAction::ACTION_OPENED, $this->newsletter->id);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(2);
   }
 
-  function testNotOpened() {
+  public function testNotOpened() {
     $emailAction = new EmailAction(EmailAction::ACTION_NOT_OPENED, $this->newsletter->id);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(1);
   }
 
-  function testGetClickedWithoutLink() {
+  public function testGetClickedWithoutLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_CLICKED, $this->newsletter->id);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(1);
   }
 
-  function testGetClickedWithLink() {
+  public function testGetClickedWithLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_CLICKED, $this->newsletter->id, 1);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(1);
   }
 
-  function testGetClickedWithWrongLink() {
+  public function testGetClickedWithWrongLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_CLICKED, $this->newsletter->id, 2);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(0);
   }
 
-  function testGetNotClickedWithLink() {
+  public function testGetNotClickedWithLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_NOT_CLICKED, $this->newsletter->id, 1);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(2);
   }
 
-  function testGetNotClickedWithWrongLink() {
+  public function testGetNotClickedWithWrongLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_NOT_CLICKED, $this->newsletter->id, 2);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(3);
   }
 
-  function testGetNotClickedWithoutLink() {
+  public function testGetNotClickedWithoutLink() {
     $emailAction = new EmailAction(EmailAction::ACTION_NOT_CLICKED, $this->newsletter->id);
     $sql = $emailAction->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(2);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/Filters/UserRoleTest.php b/tests/integration/DynamicSegments/Filters/UserRoleTest.php
index 93f670134b..28431dfd6f 100644
--- a/tests/integration/DynamicSegments/Filters/UserRoleTest.php
+++ b/tests/integration/DynamicSegments/Filters/UserRoleTest.php
@@ -6,7 +6,7 @@ use MailPoet\Models\Subscriber;
 
 class UserRoleTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
     wp_insert_user([
       'user_login' => 'user-role-test1',
@@ -28,19 +28,19 @@ class UserRoleTest extends \MailPoetTest {
     ]);
   }
 
-  function testItConstructsQuery() {
+  public function testItConstructsQuery() {
     $userRole = new UserRole('editor', 'and');
     $sql = $userRole->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(2);
   }
 
-  function testItDoesntGetSubString() {
+  public function testItDoesntGetSubString() {
     $userRole = new UserRole('edit', 'and');
     $sql = $userRole->toSql(Subscriber::selectExpr('*'));
     expect($sql->count())->equals(0);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/FreePluginConnectors/AddToNewslettersSegmentsTest.php b/tests/integration/DynamicSegments/FreePluginConnectors/AddToNewslettersSegmentsTest.php
index 4069c0d649..8ea04fc98c 100644
--- a/tests/integration/DynamicSegments/FreePluginConnectors/AddToNewslettersSegmentsTest.php
+++ b/tests/integration/DynamicSegments/FreePluginConnectors/AddToNewslettersSegmentsTest.php
@@ -8,7 +8,7 @@ use MailPoet\Models\DynamicSegment;
 
 class AddToNewslettersSegmentsTest extends \MailPoetTest {
 
-  function testItReturnsOriginalArray() {
+  public function testItReturnsOriginalArray() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment1',
@@ -26,7 +26,7 @@ class AddToNewslettersSegmentsTest extends \MailPoetTest {
     expect($result)->equals([$dynamic_segment]);
   }
 
-  function testItAddsDynamicSegments() {
+  public function testItAddsDynamicSegments() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment2',
diff --git a/tests/integration/DynamicSegments/FreePluginConnectors/AddToSubscribersFiltersTest.php b/tests/integration/DynamicSegments/FreePluginConnectors/AddToSubscribersFiltersTest.php
index 40f38476a6..bb41dbe1f7 100644
--- a/tests/integration/DynamicSegments/FreePluginConnectors/AddToSubscribersFiltersTest.php
+++ b/tests/integration/DynamicSegments/FreePluginConnectors/AddToSubscribersFiltersTest.php
@@ -8,7 +8,7 @@ use MailPoet\Models\DynamicSegment;
 
 class AddToSubscribersFiltersTest extends \MailPoetTest {
 
-  function testItReturnsOriginalArray() {
+  public function testItReturnsOriginalArray() {
     $original_segment = [
       'label' => 'segment1',
       'value' => '',
@@ -25,7 +25,7 @@ class AddToSubscribersFiltersTest extends \MailPoetTest {
     expect($result)->equals([$original_segment]);
   }
 
-  function testItAddsDynamicSegments() {
+  public function testItAddsDynamicSegments() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment2',
@@ -54,7 +54,7 @@ class AddToSubscribersFiltersTest extends \MailPoetTest {
     ]);
   }
 
-  function testItSortsTheResult() {
+  public function testItSortsTheResult() {
     $dynamic_segment1 = DynamicSegment::create();
     $dynamic_segment1->hydrate([
       'name' => 'segment b',
diff --git a/tests/integration/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinderTest.php b/tests/integration/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinderTest.php
index 93e1725e0c..f56dad3c73 100644
--- a/tests/integration/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinderTest.php
+++ b/tests/integration/DynamicSegments/FreePluginConnectors/SendingNewslettersSubscribersFinderTest.php
@@ -20,13 +20,13 @@ class SendingNewslettersSubscribersFinderTest extends \MailPoetTest {
   /** @var SendingNewslettersSubscribersFinder */
   private $subscribers_in_segments_finder;
 
-  function _before() {
+  public function _before() {
     $this->single_segment_loader = Stub::makeEmpty('\MailPoet\DynamicSegments\Persistence\Loading\SingleSegmentLoader');
     $this->subscribers_ids_loader = Stub::makeEmpty('\MailPoet\DynamicSegments\Persistence\Loading\SubscribersIds');
     $this->subscribers_in_segments_finder = new SendingNewslettersSubscribersFinder($this->single_segment_loader, $this->subscribers_ids_loader);
   }
 
-  function testFindSubscribersInSegmentReturnsEmptyIfNotDynamic() {
+  public function testFindSubscribersInSegmentReturnsEmptyIfNotDynamic() {
     $this->single_segment_loader
       ->expects($this->never())
       ->method('load');
@@ -40,7 +40,7 @@ class SendingNewslettersSubscribersFinderTest extends \MailPoetTest {
     expect($result)->count(0);
   }
 
-  function testFindSubscribersInSegmentReturnsSubscribers() {
+  public function testFindSubscribersInSegmentReturnsSubscribers() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment 1',
@@ -65,7 +65,7 @@ class SendingNewslettersSubscribersFinderTest extends \MailPoetTest {
   }
 
 
-  function testGetSubscriberIdsInSegmentReturnsEmptyIfNotDynamic() {
+  public function testGetSubscriberIdsInSegmentReturnsEmptyIfNotDynamic() {
     $this->single_segment_loader
       ->expects($this->never())
       ->method('load');
@@ -78,7 +78,7 @@ class SendingNewslettersSubscribersFinderTest extends \MailPoetTest {
     expect($result)->count(0);
   }
 
-  function testGetSubscriberIdsInSegmentReturnsSubscribers() {
+  public function testGetSubscriberIdsInSegmentReturnsSubscribers() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment 2',
diff --git a/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandlerTest.php b/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandlerTest.php
index 8d4862ad82..41b8253478 100644
--- a/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandlerTest.php
+++ b/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersBulkActionHandlerTest.php
@@ -7,7 +7,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SubscribersBulkActionHandlerTest extends \MailPoetTest {
 
-  function testItReturnsNullWithUnknownSegment() {
+  public function testItReturnsNullWithUnknownSegment() {
     $segment = [
       'name' => 'name',
       'description' => 'desc',
@@ -21,7 +21,7 @@ class SubscribersBulkActionHandlerTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItReturnsDataForDynamicSegment() {
+  public function testItReturnsDataForDynamicSegment() {
     $segment = DynamicSegment::createOrUpdate([
       'name' => 'name',
       'description' => 'desc',
@@ -35,11 +35,11 @@ class SubscribersBulkActionHandlerTest extends \MailPoetTest {
     expect($result)->notNull();
   }
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactoryTest.php b/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactoryTest.php
index fdbf88b4ed..8b4a0319bb 100644
--- a/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactoryTest.php
+++ b/tests/integration/DynamicSegments/FreePluginConnectors/SubscribersListingsHandlerFactoryTest.php
@@ -7,7 +7,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SubscribersListingsHandlerFactoryTest extends \MailPoetTest {
 
-  function testItReturnsNullWithUnknownSegment() {
+  public function testItReturnsNullWithUnknownSegment() {
     $segment = DynamicSegment::create();
     $segment->id = 1;
     $segment->name = 'name';
@@ -17,7 +17,7 @@ class SubscribersListingsHandlerFactoryTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItReturnsDataForDynamicSegment() {
+  public function testItReturnsDataForDynamicSegment() {
     $segment = DynamicSegment::createOrUpdate([
       'name' => 'name',
       'description' => 'desc',
@@ -28,11 +28,11 @@ class SubscribersListingsHandlerFactoryTest extends \MailPoetTest {
     expect($result)->notNull();
   }
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/Mappers/FormDataMapperTest.php b/tests/integration/DynamicSegments/Mappers/FormDataMapperTest.php
index 6272266a19..400341b869 100644
--- a/tests/integration/DynamicSegments/Mappers/FormDataMapperTest.php
+++ b/tests/integration/DynamicSegments/Mappers/FormDataMapperTest.php
@@ -9,7 +9,7 @@ class FormDataMapperTest extends \MailPoetTest {
   /** @var FormDataMapper */
   private $mapper;
 
-  function _before() {
+  public function _before() {
     $this->mapper = new FormDataMapper();
   }
 
diff --git a/tests/integration/DynamicSegments/Persistence/Loading/LoaderTest.php b/tests/integration/DynamicSegments/Persistence/Loading/LoaderTest.php
index eef3eb9ee0..2080de3598 100644
--- a/tests/integration/DynamicSegments/Persistence/Loading/LoaderTest.php
+++ b/tests/integration/DynamicSegments/Persistence/Loading/LoaderTest.php
@@ -15,7 +15,7 @@ class LoaderTest extends \MailPoetTest {
   /** @var Loader */
   private $loader;
 
-  function _before() {
+  public function _before() {
     $this->loader = new Loader(new DBMapper());
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
@@ -43,14 +43,14 @@ class LoaderTest extends \MailPoetTest {
     $filter_data->save();
   }
 
-  function testItLoadsSegments() {
+  public function testItLoadsSegments() {
     $data = $this->loader->load();
     expect($data)->count(2);
     expect($data[0])->isInstanceOf('\MailPoet\Models\DynamicSegment');
     expect($data[1])->isInstanceOf('\MailPoet\Models\DynamicSegment');
   }
 
-  function testItDoesNotLoadTrashedSegments() {
+  public function testItDoesNotLoadTrashedSegments() {
     $this->segments[0]->trash();
     $data = $this->loader->load();
     expect($data)->count(1);
@@ -58,7 +58,7 @@ class LoaderTest extends \MailPoetTest {
     expect($data[0]->name)->equals('segment 2');
   }
 
-  function testItPopulatesCommonData() {
+  public function testItPopulatesCommonData() {
     $data = $this->loader->load();
     expect($data[0]->name)->equals('segment 1');
     expect($data[1]->name)->equals('segment 2');
@@ -66,7 +66,7 @@ class LoaderTest extends \MailPoetTest {
     expect($data[1]->description)->equals('description');
   }
 
-  function testItPopulatesFilters() {
+  public function testItPopulatesFilters() {
     $data = $this->loader->load();
     $filters0 = $data[0]->getFilters();
     $filters1 = $data[1]->getFilters();
@@ -78,7 +78,7 @@ class LoaderTest extends \MailPoetTest {
     expect($filters1[0]->getRole())->equals('Administrator');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
   }
diff --git a/tests/integration/DynamicSegments/Persistence/Loading/SingleSegmentLoaderTest.php b/tests/integration/DynamicSegments/Persistence/Loading/SingleSegmentLoaderTest.php
index c0e6877601..a990171fe9 100644
--- a/tests/integration/DynamicSegments/Persistence/Loading/SingleSegmentLoaderTest.php
+++ b/tests/integration/DynamicSegments/Persistence/Loading/SingleSegmentLoaderTest.php
@@ -15,7 +15,7 @@ class SingleSegmentLoaderTest extends \MailPoetTest {
   /** @var SingleSegmentLoader */
   private $loader;
 
-  function _before() {
+  public function _before() {
     $this->loader = new SingleSegmentLoader(new DBMapper());
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
@@ -32,23 +32,23 @@ class SingleSegmentLoaderTest extends \MailPoetTest {
     $filter_data->save();
   }
 
-  function testItLoadsSegments() {
+  public function testItLoadsSegments() {
     $data = $this->loader->load($this->segment->id);
     expect($data)->isInstanceOf('\MailPoet\Models\DynamicSegment');
   }
 
-  function testItThrowsForUnknownSegment() {
+  public function testItThrowsForUnknownSegment() {
     $this->setExpectedException('InvalidArgumentException');
     $this->loader->load($this->segment->id + 11564564);
   }
 
-  function testItPopulatesCommonData() {
+  public function testItPopulatesCommonData() {
     $data = $this->loader->load($this->segment->id);
     expect($data->name)->equals('segment 1');
     expect($data->description)->equals('description');
   }
 
-  function testItPopulatesFilters() {
+  public function testItPopulatesFilters() {
     $data = $this->loader->load($this->segment->id);
     $filters0 = $data->getFilters();
     expect($filters0)->count(1);
@@ -56,7 +56,7 @@ class SingleSegmentLoaderTest extends \MailPoetTest {
     expect($filters0[0]->getRole())->equals('Administrator');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
   }
diff --git a/tests/integration/DynamicSegments/Persistence/Loading/SubscribersCountTest.php b/tests/integration/DynamicSegments/Persistence/Loading/SubscribersCountTest.php
index cee69c0650..a92f6244e7 100644
--- a/tests/integration/DynamicSegments/Persistence/Loading/SubscribersCountTest.php
+++ b/tests/integration/DynamicSegments/Persistence/Loading/SubscribersCountTest.php
@@ -13,7 +13,7 @@ class SubscribersCountTest extends \MailPoetTest {
   /** @var RequirementsChecker|\PHPUnit_Framework_MockObject_MockObject */
   private $requirement_checker;
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
     wp_insert_user([
       'user_login' => 'user-role-test1',
@@ -39,7 +39,7 @@ class SubscribersCountTest extends \MailPoetTest {
       ->getMock();
   }
 
-  function testItConstructsQuery() {
+  public function testItConstructsQuery() {
     $this->requirement_checker->method('shouldSkipSegment')->willReturn(false);
     $userRole = DynamicSegment::create();
     $userRole->hydrate([
@@ -53,7 +53,7 @@ class SubscribersCountTest extends \MailPoetTest {
     expect($count)->equals(2);
   }
 
-  function testItSkipsIfRequirementNotMet() {
+  public function testItSkipsIfRequirementNotMet() {
     $this->requirement_checker->method('shouldSkipSegment')->willReturn(true);
     $userRole = DynamicSegment::create();
     $userRole->hydrate([
@@ -67,7 +67,7 @@ class SubscribersCountTest extends \MailPoetTest {
     expect($count)->equals(0);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/Persistence/Loading/SubscribersIdsTest.php b/tests/integration/DynamicSegments/Persistence/Loading/SubscribersIdsTest.php
index 41b0276528..e1dc8688b1 100644
--- a/tests/integration/DynamicSegments/Persistence/Loading/SubscribersIdsTest.php
+++ b/tests/integration/DynamicSegments/Persistence/Loading/SubscribersIdsTest.php
@@ -16,7 +16,7 @@ class SubscribersIdsTest extends \MailPoetTest {
   /** @var RequirementsChecker|\PHPUnit_Framework_MockObject_MockObject */
   private $requirement_checker;
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
     $this->editors_wp_ids[] = wp_insert_user([
       'user_login' => 'user-role-test1',
@@ -42,7 +42,7 @@ class SubscribersIdsTest extends \MailPoetTest {
       ->getMock();
   }
 
-  function testItConstructsSubscribersIdQueryForAnyDynamicSegment() {
+  public function testItConstructsSubscribersIdQueryForAnyDynamicSegment() {
     $this->requirement_checker->method('shouldSkipSegment')->willReturn(false);
     $userRole = DynamicSegment::create();
     $userRole->hydrate([
@@ -59,7 +59,7 @@ class SubscribersIdsTest extends \MailPoetTest {
     $this->assertEquals($wp_ids, $this->editors_wp_ids, $message = '', $delta = 0.0, $maxDepth = 10, $canonicalize = true);
   }
 
-  function testItSkipsConstructingSubscribersIdQueryForAnyDynamicSegmentIfRequirementsNotMet() {
+  public function testItSkipsConstructingSubscribersIdQueryForAnyDynamicSegmentIfRequirementsNotMet() {
     $this->requirement_checker->method('shouldSkipSegment')->willReturn(true);
     $userRole = DynamicSegment::create();
     $userRole->hydrate([
@@ -72,7 +72,7 @@ class SubscribersIdsTest extends \MailPoetTest {
     expect($result)->isEmpty();
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/DynamicSegments/Persistence/SaverTest.php b/tests/integration/DynamicSegments/Persistence/SaverTest.php
index 2626e212ac..b37e7d8d3f 100644
--- a/tests/integration/DynamicSegments/Persistence/SaverTest.php
+++ b/tests/integration/DynamicSegments/Persistence/SaverTest.php
@@ -13,18 +13,18 @@ class SaverTest extends \MailPoetTest {
   /** @var  Saver */
   private $saver;
 
-  function _before() {
+  public function _before() {
     $this->saver = new Saver();
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . DynamicSegment::$_table);
     ORM::raw_execute('TRUNCATE ' . DynamicSegmentFilter::$_table);
   }
 
-  function testItSavesSegment() {
+  public function testItSavesSegment() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment 1',
@@ -36,7 +36,7 @@ class SaverTest extends \MailPoetTest {
     expect($loaded->description)->equals('desc');
   }
 
-  function testItThrowsOnDuplicateSegment() {
+  public function testItThrowsOnDuplicateSegment() {
     $dynamic_segment1 = DynamicSegment::createOrUpdate([
       'name' => 'segment 1',
       'description' => 'description',
@@ -51,7 +51,7 @@ class SaverTest extends \MailPoetTest {
     $this->saver->save($dynamic_segment2);
   }
 
-  function testItSavesFilters() {
+  public function testItSavesFilters() {
     $dynamic_segment = DynamicSegment::create();
     $dynamic_segment->hydrate([
       'name' => 'segment 1',
diff --git a/tests/integration/Form/Block/SelectTest.php b/tests/integration/Form/Block/SelectTest.php
index 88b799dd35..ec915f0678 100644
--- a/tests/integration/Form/Block/SelectTest.php
+++ b/tests/integration/Form/Block/SelectTest.php
@@ -6,7 +6,7 @@ use MailPoet\Form\Block\Select;
 use MailPoet\Models\Subscriber;
 
 class SelectTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->block = [
       'id' => 'status',
@@ -40,26 +40,26 @@ class SelectTest extends \MailPoetTest {
     ];
   }
 
-  function testItRendersSelectBlock() {
+  public function testItRendersSelectBlock() {
     $rendered = Select::render($this->block);
     expect($rendered)->contains(Subscriber::STATUS_SUBSCRIBED);
     expect($rendered)->contains(Subscriber::STATUS_UNSUBSCRIBED);
     expect($rendered)->contains(Subscriber::STATUS_BOUNCED);
   }
 
-  function testItRendersSelectedOption() {
+  public function testItRendersSelectedOption() {
     $this->block['params']['values'][0]['is_checked'] = true;
     $rendered = Select::render($this->block);
     expect($rendered)->contains('selected="selected"');
   }
 
-  function testItRendersDisabledOptions() {
+  public function testItRendersDisabledOptions() {
     $this->block['params']['values'][2]['is_disabled'] = true;
     $rendered = Select::render($this->block);
     expect($rendered)->contains('disabled="disabled"');
   }
 
-  function testItDoesNotRenderHiddenOptions() {
+  public function testItDoesNotRenderHiddenOptions() {
     $this->block['params']['values'][2]['is_hidden'] = true;
     $rendered = Select::render($this->block);
     expect($rendered)->notContains(Subscriber::STATUS_BOUNCED);
diff --git a/tests/integration/Form/WidgetTest.php b/tests/integration/Form/WidgetTest.php
index f48f53efe5..ef7c399e62 100644
--- a/tests/integration/Form/WidgetTest.php
+++ b/tests/integration/Form/WidgetTest.php
@@ -8,7 +8,7 @@ use MailPoet\Util\pQuery\pQuery;
 use MailPoet\WP\Functions as WPFunctions;
 
 class WidgetTest extends \MailPoetTest {
-  function testItAllowsModifyingRenderedFormWidgetViaHook() {
+  public function testItAllowsModifyingRenderedFormWidgetViaHook() {
     $form = Form::createOrUpdate(
       [
         'name' => 'Test Form',
diff --git a/tests/integration/Helpscout/BeaconTest.php b/tests/integration/Helpscout/BeaconTest.php
index 0e20971000..c67c8633d9 100644
--- a/tests/integration/Helpscout/BeaconTest.php
+++ b/tests/integration/Helpscout/BeaconTest.php
@@ -9,7 +9,7 @@ use MailPoet\Settings\SettingsController;
 use MailPoet\WP\Functions as WPFunctions;
 
 class BeaconTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // create 4 users (1 confirmed, 1 subscribed, 1 unsubscribed, 1 bounced)
     Subscriber::createOrUpdate([
@@ -33,78 +33,78 @@ class BeaconTest extends \MailPoetTest {
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItReturnsPhpVersion() {
+  public function testItReturnsPhpVersion() {
     expect($this->beacon_data['PHP version'])->equals(PHP_VERSION);
   }
 
-  function testItReturnsMailpoetVersion() {
+  public function testItReturnsMailpoetVersion() {
     expect($this->beacon_data['MailPoet Free version'])->equals(MAILPOET_VERSION);
   }
 
-  function testItReturnsWordpressVersion() {
+  public function testItReturnsWordpressVersion() {
     expect($this->beacon_data['WordPress version'])->equals(get_bloginfo('version'));
   }
 
-  function testItReturnsDatabaseVersion() {
+  public function testItReturnsDatabaseVersion() {
     global $wpdb;
     $db_version = $wpdb->get_var('SELECT @@VERSION');
     expect($this->beacon_data['Database version'])->equals($db_version);
   }
 
-  function testItReturnsWpMemoryLimit() {
+  public function testItReturnsWpMemoryLimit() {
     expect($this->beacon_data['WP_MEMORY_LIMIT'])->equals(WP_MEMORY_LIMIT);
   }
 
-  function testItReturnsWpMaxMemoryLimit() {
+  public function testItReturnsWpMaxMemoryLimit() {
     expect($this->beacon_data['WP_MAX_MEMORY_LIMIT'])->equals(WP_MAX_MEMORY_LIMIT);
   }
 
-  function testItReturnsWpDebugValue() {
+  public function testItReturnsWpDebugValue() {
     expect($this->beacon_data['WP_DEBUG'])->equals(WP_DEBUG);
   }
 
-  function testItReturnsPhpMaxExecutionTime() {
+  public function testItReturnsPhpMaxExecutionTime() {
     expect($this->beacon_data['PHP max_execution_time'])->equals(ini_get('max_execution_time'));
   }
 
-  function testItReturnsPhpMemoryLimit() {
+  public function testItReturnsPhpMemoryLimit() {
     expect($this->beacon_data['PHP memory_limit'])->equals(ini_get('memory_limit'));
   }
 
-  function testItReturnsPhpUploadMaxFilesize() {
+  public function testItReturnsPhpUploadMaxFilesize() {
     expect($this->beacon_data['PHP upload_max_filesize'])->equals(ini_get('upload_max_filesize'));
   }
 
-  function testItReturnsPhpPostMaxSize() {
+  public function testItReturnsPhpPostMaxSize() {
     expect($this->beacon_data['PHP post_max_size'])->equals(ini_get('post_max_size'));
   }
 
-  function testItReturnsWpLanguage() {
+  public function testItReturnsWpLanguage() {
     expect($this->beacon_data['WordPress language'])->equals(get_locale());
   }
 
-  function testItReturnsIfWpIsMultisite() {
+  public function testItReturnsIfWpIsMultisite() {
     expect($this->beacon_data['Multisite environment?'])->equals(is_multisite() ? 'Yes' : 'No');
   }
 
-  function testItReturnsCurrentThemeNameAndVersion() {
+  public function testItReturnsCurrentThemeNameAndVersion() {
     $current_theme = wp_get_theme();
     expect($this->beacon_data['Current Theme'])->contains($current_theme->get('Name'));
     expect($this->beacon_data['Current Theme'])->contains($current_theme->get('Version'));
   }
 
-  function testItReturnsActivePlugins() {
+  public function testItReturnsActivePlugins() {
     expect($this->beacon_data['Active Plugin names'])->equals(join(", ", get_option('active_plugins')));
   }
 
-  function testItReturnsSendingMethodDetails() {
+  public function testItReturnsSendingMethodDetails() {
     $mta = $this->settings->get('mta');
     expect($this->beacon_data['Sending Method'])->equals($mta['method']);
     expect($this->beacon_data['Sending Frequency'])->contains($mta['frequency']['emails'] . ' emails');
     expect($this->beacon_data['Sending Frequency'])->contains($mta['frequency']['interval'] . ' minutes');
   }
 
-  function testItReturnsSomeSettings() {
+  public function testItReturnsSomeSettings() {
     expect($this->beacon_data['Task Scheduler method'])->equals($this->settings->get('cron_trigger.method'));
     expect($this->beacon_data['Default FROM address'])->equals($this->settings->get('sender.address'));
     expect($this->beacon_data['Default Reply-To address'])->equals($this->settings->get('reply_to.address'));
@@ -112,22 +112,22 @@ class BeaconTest extends \MailPoetTest {
     expect($this->beacon_data['Plugin installed at'])->equals($this->settings->get('installed_at'));
   }
 
-  function testItReturnsTotalNumberOfSubscribers() {
+  public function testItReturnsTotalNumberOfSubscribers() {
     // unsubscribed users are not taken into account
     expect($this->beacon_data['Total number of subscribers'])->equals(2);
   }
 
-  function testItReturnsWebserverInformation() {
+  public function testItReturnsWebserverInformation() {
     expect($this->beacon_data['Web server'])->equals(
       (!empty($_SERVER["SERVER_SOFTWARE"])) ? $_SERVER["SERVER_SOFTWARE"] : 'N/A'
     );
   }
 
-  function testItReturnsServerOSInformation() {
+  public function testItReturnsServerOSInformation() {
     expect($this->beacon_data['Server OS'])->equals(utf8_encode(php_uname()));
   }
 
-  function testItReturnsCronPingUrl() {
+  public function testItReturnsCronPingUrl() {
     expect($this->beacon_data['Cron ping URL'])->contains('&action=ping');
     // cron ping URL should react to custom filters
     $filter = function($url) {
@@ -140,13 +140,13 @@ class BeaconTest extends \MailPoetTest {
     $wp->removeFilter('mailpoet_cron_request_url', $filter);
   }
 
-  function testItReturnsPremiumVersion() {
+  public function testItReturnsPremiumVersion() {
     expect($this->beacon_data['MailPoet Premium version'])->equals(
       (defined('MAILPOET_PREMIUM_VERSION')) ? MAILPOET_PREMIUM_VERSION : 'N/A'
     );
   }
 
-  function testItReturnsPremiumKey() {
+  public function testItReturnsPremiumKey() {
     expect($this->beacon_data['MailPoet Premium/MSS key'])->equals(
       $this->settings->get(Bridge::PREMIUM_KEY_SETTING_NAME) ?: $this->settings->get(Bridge::API_KEY_SETTING_NAME)
     );
diff --git a/tests/integration/Listing/BulkActionClassStub.php b/tests/integration/Listing/BulkActionClassStub.php
index b4e36bf8ff..e5b73fc930 100644
--- a/tests/integration/Listing/BulkActionClassStub.php
+++ b/tests/integration/Listing/BulkActionClassStub.php
@@ -4,7 +4,7 @@ namespace MailPoet\Listing;
 
 class BulkActionClassStub {
 
-  function bulkTestAction() {
+  public function bulkTestAction() {
 
   }
 
diff --git a/tests/integration/Listing/BulkActionFactoryTest.php b/tests/integration/Listing/BulkActionFactoryTest.php
index f5a53b2386..3a58c2ac31 100644
--- a/tests/integration/Listing/BulkActionFactoryTest.php
+++ b/tests/integration/Listing/BulkActionFactoryTest.php
@@ -10,11 +10,11 @@ class BulkActionFactoryTest extends \MailPoetTest {
   /** @var BulkActionFactory */
   private $bulk_action_factory;
 
-  function _before() {
+  public function _before() {
     $this->bulk_action_factory = new BulkActionFactory();
   }
 
-  function testItReturnsCustomActionClass() {
+  public function testItReturnsCustomActionClass() {
     $model_class = Subscriber::class;
     $method = 'bulkTestAction';
     $action_class = new BulkActionClassStub;
@@ -23,7 +23,7 @@ class BulkActionFactoryTest extends \MailPoetTest {
     expect($resulting_class)->equals($action_class);
   }
 
-  function testItThrowsIfANonExistentActionMethodIsBeingRegistered() {
+  public function testItThrowsIfANonExistentActionMethodIsBeingRegistered() {
     $model_class = Subscriber::class;
     $method = 'bulkDoesNotExist';
     $action_class = new BulkActionClassStub;
@@ -35,7 +35,7 @@ class BulkActionFactoryTest extends \MailPoetTest {
     }
   }
 
-  function testItThrowsIfANonExistentActionClassIsBeingRegistered() {
+  public function testItThrowsIfANonExistentActionClassIsBeingRegistered() {
     $model_class = Subscriber::class;
     $method = 'bulkDoesNotExist';
     $action_class = '\MailPoet\Some\Non\Existent\Class';
@@ -47,14 +47,14 @@ class BulkActionFactoryTest extends \MailPoetTest {
     }
   }
 
-  function testItReturnsModelClassByDefault() {
+  public function testItReturnsModelClassByDefault() {
     $model_class = Subscriber::class;
     $method = 'bulkTrash';
     $resulting_class = $this->bulk_action_factory->getActionClass($model_class, $method);
     expect($resulting_class)->equals($model_class);
   }
 
-  function testItThrowsIfANonExistentModelMethodIsProvided() {
+  public function testItThrowsIfANonExistentModelMethodIsProvided() {
     $model_class = Subscriber::class;
     $method = 'bulkDoesNotExist';
     try {
diff --git a/tests/integration/Logging/LogHandlerTest.php b/tests/integration/Logging/LogHandlerTest.php
index 2bdf83b355..cdda6ffe74 100644
--- a/tests/integration/Logging/LogHandlerTest.php
+++ b/tests/integration/Logging/LogHandlerTest.php
@@ -76,7 +76,7 @@ class LogHandlerTest extends \MailPoetTest {
     expect($log)->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Log::$_table);
   }
 
diff --git a/tests/integration/Mailer/MailerLogTest.php b/tests/integration/Mailer/MailerLogTest.php
index f763106cff..cea32b973c 100644
--- a/tests/integration/Mailer/MailerLogTest.php
+++ b/tests/integration/Mailer/MailerLogTest.php
@@ -12,12 +12,12 @@ class MailerLogTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItGetsMailerLogWhenOneExists() {
+  public function testItGetsMailerLogWhenOneExists() {
     $mailer_log = [
       'sent' => 0,
       'started' => time(),
@@ -26,19 +26,19 @@ class MailerLogTest extends \MailPoetTest {
     expect(MailerLog::getMailerLog())->equals($mailer_log);
   }
 
-  function testItGetsMailerLogWhenOneDoesNotExist() {
+  public function testItGetsMailerLogWhenOneDoesNotExist() {
     $mailer_log = MailerLog::getMailerLog();
     expect($mailer_log['sent'])->equals(0);
     expect(strlen($mailer_log['started']))->greaterThan(5);
   }
 
-  function testItCreatesMailer() {
+  public function testItCreatesMailer() {
     $mailer_log = MailerLog::createMailerLog();
     expect($mailer_log['sent'])->equals(0);
     expect(strlen($mailer_log['started']))->greaterThan(5);
   }
 
-  function testItResetsMailerLog() {
+  public function testItResetsMailerLog() {
     $mailer_log = [
       'sent' => 1,
       'started' => time() - 10,
@@ -50,7 +50,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($updated_mailer_log['started'])->greaterThan($mailer_log['started']);
   }
 
-  function testItUpdatesMailerLog() {
+  public function testItUpdatesMailerLog() {
     $mailer_log = [
       'sent' => 1,
       'started' => time() - 10,
@@ -60,7 +60,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($updated_mailer_log)->equals($mailer_log);
   }
 
-  function testItIncrementsSentCount() {
+  public function testItIncrementsSentCount() {
     $mailer_log = [
       'sent' => 1,
       'started' => time(),
@@ -72,7 +72,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($updated_mailer_log['sent'])->equals(2);
   }
 
-  function testItChecksWhenSendingLimitIsReached() {
+  public function testItChecksWhenSendingLimitIsReached() {
     $mailer_config = [
       'frequency' => [
         'emails' => 2,
@@ -98,14 +98,14 @@ class MailerLogTest extends \MailPoetTest {
     expect(MailerLog::isSendingLimitReached())->true();
   }
 
-  function testItChecksWhenSendingIsPaused() {
+  public function testItChecksWhenSendingIsPaused() {
     $mailer_log = ['status' => MailerLog::STATUS_PAUSED];
     expect(MailerLog::isSendingPaused($mailer_log))->true();
     $mailer_log = ['status' => false];
     expect(MailerLog::isSendingPaused($mailer_log))->false();
   }
 
-  function testItResetsMailerAfterSendingLimitWaitPeriodIsOver() {
+  public function testItResetsMailerAfterSendingLimitWaitPeriodIsOver() {
     $mailer_config = [
       'frequency' => [
         'emails' => 2,
@@ -127,7 +127,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($updated_mailer_log['sent'])->equals(0);
   }
 
-  function testItResumesSending() {
+  public function testItResumesSending() {
     // set status to "paused"
     $mailer_log = ['status' => MailerLog::STATUS_PAUSED];
     MailerLog::updateMailerLog($mailer_log);
@@ -139,7 +139,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($mailer_log['status'])->null();
   }
 
-  function testItPausesSending() {
+  public function testItPausesSending() {
     $mailer_log = [
       'status' => null,
       'retry_attempt' => MailerLog::RETRY_ATTEMPTS_LIMIT,
@@ -153,7 +153,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($mailer_log['retry_at'])->null();
   }
 
-  function testItProcessesSendingError() {
+  public function testItProcessesSendingError() {
     // retry-related mailer values should be null
     $mailer_log = MailerLog::getMailerLog();
     expect($mailer_log['retry_attempt'])->null();
@@ -173,7 +173,7 @@ class MailerLogTest extends \MailPoetTest {
     );
   }
 
-  function testItProcessesNonBlockingSendingError() {
+  public function testItProcessesNonBlockingSendingError() {
     $mailer_log = MailerLog::getMailerLog();
     expect($mailer_log['retry_attempt'])->null();
     expect($mailer_log['retry_at'])->null();
@@ -191,7 +191,7 @@ class MailerLogTest extends \MailPoetTest {
     );
   }
 
-  function testItPausesSendingAfterProcessingSendingError() {
+  public function testItPausesSendingAfterProcessingSendingError() {
     $mailer_log = MailerLog::getMailerLog();
     expect($mailer_log['error'])->null();
     try {
@@ -212,7 +212,7 @@ class MailerLogTest extends \MailPoetTest {
     );
   }
 
-  function testItEnforcesSendingLimit() {
+  public function testItEnforcesSendingLimit() {
     $mailer_config = [
       'frequency' => [
         'emails' => 2,
@@ -234,7 +234,7 @@ class MailerLogTest extends \MailPoetTest {
     }
   }
 
-  function testItEnsuresSendingLimitIsEnforcedAfterFrequencyIsLowered() {
+  public function testItEnsuresSendingLimitIsEnforcedAfterFrequencyIsLowered() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['sent'] = 10;
     $mailer_log['started'] = time();
@@ -256,7 +256,7 @@ class MailerLogTest extends \MailPoetTest {
     }
   }
 
-  function testItEnsuresSendingLimitIsNotEnforcedAfterFrequencyIsIncreased() {
+  public function testItEnsuresSendingLimitIsNotEnforcedAfterFrequencyIsIncreased() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['sent'] = 10;
     $mailer_log['started'] = time();
@@ -277,7 +277,7 @@ class MailerLogTest extends \MailPoetTest {
     }
   }
 
-  function testItEnforcesRetryAtTime() {
+  public function testItEnforcesRetryAtTime() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['retry_at'] = time() + 10;
     // exception is thrown when current time is sooner than 120 seconds
@@ -289,7 +289,7 @@ class MailerLogTest extends \MailPoetTest {
     }
   }
 
-  function testItEnforcesRetryAttempts() {
+  public function testItEnforcesRetryAttempts() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['retry_attempt'] = 2;
     // allow less than 3 attempts
@@ -306,7 +306,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($mailer_log['status'])->equals(MailerLog::STATUS_PAUSED);
   }
 
-  function testItClearsSendingErrorLog() {
+  public function testItClearsSendingErrorLog() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['retry_attempt'] = 1;
     $mailer_log['retry_at'] = 1;
@@ -319,7 +319,7 @@ class MailerLogTest extends \MailPoetTest {
     expect($mailer_log['status'])->equals('status');
   }
 
-  function testItEnforcesPausedStatus() {
+  public function testItEnforcesPausedStatus() {
     $mailer_log = MailerLog::createMailerLog();
     $mailer_log['status'] = MailerLog::STATUS_PAUSED;
     try {
@@ -330,7 +330,7 @@ class MailerLogTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Mailer/MailerTest.php b/tests/integration/Mailer/MailerTest.php
index 8ca477324c..b8e7b078b9 100644
--- a/tests/integration/Mailer/MailerTest.php
+++ b/tests/integration/Mailer/MailerTest.php
@@ -11,7 +11,7 @@ class MailerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->available_mailer_methods = [
       [
@@ -67,7 +67,7 @@ class MailerTest extends \MailPoetTest {
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItRequiresMailerMethod() {
+  public function testItRequiresMailerMethod() {
     // reset mta settings so that we have no default mailer
     $this->settings->set('mta', null);
     try {
@@ -79,7 +79,7 @@ class MailerTest extends \MailPoetTest {
     }
   }
 
-  function testItRequiresSender() {
+  public function testItRequiresSender() {
     try {
       $mailer = new Mailer();
       $mailer->init($mailer = $this->mailer);
@@ -89,7 +89,7 @@ class MailerTest extends \MailPoetTest {
     }
   }
 
-  function testItCanConstruct() {
+  public function testItCanConstruct() {
     $mailer = new Mailer();
     $mailer->init($this->mailer, $this->sender, $this->reply_to, $this->return_path);
     expect($mailer->sender['from_name'])->equals($this->sender['name']);
@@ -99,7 +99,7 @@ class MailerTest extends \MailPoetTest {
     expect($mailer->return_path)->equals($this->return_path);
   }
 
-  function testItThrowsUnknownMailerException() {
+  public function testItThrowsUnknownMailerException() {
     try {
       $mailer = new Mailer();
       $mailer->init(['method' => 'Unknown'], $this->sender);
@@ -109,7 +109,7 @@ class MailerTest extends \MailPoetTest {
     }
   }
 
-  function testItSetsReplyToAddressWhenOnlyNameIsAvailable() {
+  public function testItSetsReplyToAddressWhenOnlyNameIsAvailable() {
     $reply_to = ['name' => 'test'];
     $mailer = new Mailer();
     $mailer->init($this->mailer, $this->sender, $reply_to);
@@ -117,7 +117,7 @@ class MailerTest extends \MailPoetTest {
     expect($reply_to['reply_to_email'])->equals($this->sender['address']);
   }
 
-  function testItGetsReturnPathAddress() {
+  public function testItGetsReturnPathAddress() {
     $mailer = new Mailer();
     $mailer->init($this->mailer, $this->sender, $this->reply_to);
     $return_path = $mailer->getReturnPathAddress('bounce@test.com');
@@ -127,7 +127,7 @@ class MailerTest extends \MailPoetTest {
     expect($return_path)->equals('settngs_bounce@test.com');
   }
 
-  function testItCanTransformSubscriber() {
+  public function testItCanTransformSubscriber() {
     $mailer = new Mailer();
     $mailer->init($this->mailer, $this->sender, $this->reply_to);
     expect($mailer->formatSubscriberNameAndEmailAddress('test@email.com'))
@@ -164,7 +164,7 @@ class MailerTest extends \MailPoetTest {
     )->equals('First Last <test@email.com>');
   }
 
-  function testItCanConvertNonASCIIEmailAddressString() {
+  public function testItCanConvertNonASCIIEmailAddressString() {
     $mailer = new Mailer();
     $mailer->init($this->mailer, $this->sender, $this->reply_to);
     expect($mailer->sender['from_name'])->equals($this->sender['name']);
@@ -185,7 +185,7 @@ class MailerTest extends \MailPoetTest {
       ->equals(sprintf('=?utf-8?B?%s?=', base64_encode($reply_to['name'])));
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->sender['address'] = 'staff@mailpoet.com';
     $mailer = new Mailer();
@@ -194,7 +194,7 @@ class MailerTest extends \MailPoetTest {
     expect($result['response'])->true();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Mailer/MetaInfoTest.php b/tests/integration/Mailer/MetaInfoTest.php
index 70c57c0439..c644fd37bd 100644
--- a/tests/integration/Mailer/MetaInfoTest.php
+++ b/tests/integration/Mailer/MetaInfoTest.php
@@ -12,12 +12,12 @@ class MetaInfoTest extends \MailPoetTest {
   /** @var MetaInfo */
   private $meta;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->meta = new MetaInfo;
   }
 
-  function testItGetsMetaInfoForSendingTest() {
+  public function testItGetsMetaInfoForSendingTest() {
     expect($this->meta->getSendingTestMetaInfo())->equals([
       'email_type' => 'sending_test',
       'subscriber_status' => 'unknown',
@@ -25,7 +25,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForPreview() {
+  public function testItGetsMetaInfoForPreview() {
     expect($this->meta->getPreviewMetaInfo())->equals([
       'email_type' => 'preview',
       'subscriber_status' => 'unknown',
@@ -33,7 +33,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForStatsNotifications() {
+  public function testItGetsMetaInfoForStatsNotifications() {
     expect($this->meta->getStatsNotificationMetaInfo())->equals([
       'email_type' => 'email_stats_notification',
       'subscriber_status' => 'unknown',
@@ -41,7 +41,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForWordPressTransactionalEmails() {
+  public function testItGetsMetaInfoForWordPressTransactionalEmails() {
     expect($this->meta->getWordPressTransactionalMetaInfo())->equals([
       'email_type' => 'transactional',
       'subscriber_status' => 'unknown',
@@ -59,7 +59,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForConfirmationEmails() {
+  public function testItGetsMetaInfoForConfirmationEmails() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'unconfirmed',
@@ -72,7 +72,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForNewSubscriberNotifications() {
+  public function testItGetsMetaInfoForNewSubscriberNotifications() {
     expect($this->meta->getNewSubscriberNotificationMetaInfo())->equals([
       'email_type' => 'new_subscriber_notification',
       'subscriber_status' => 'unknown',
@@ -80,7 +80,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForStandardNewsletter() {
+  public function testItGetsMetaInfoForStandardNewsletter() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'subscribed',
@@ -96,7 +96,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForWelcomeEmail() {
+  public function testItGetsMetaInfoForWelcomeEmail() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'subscribed',
@@ -112,7 +112,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForPostNotification() {
+  public function testItGetsMetaInfoForPostNotification() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'subscribed',
@@ -136,7 +136,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItGetsMetaInfoForAutomaticEmails() {
+  public function testItGetsMetaInfoForAutomaticEmails() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'subscribed',
@@ -168,7 +168,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function testItSetsUnknownSubscriberSourceWhenNull() {
+  public function testItSetsUnknownSubscriberSourceWhenNull() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'status' => 'subscribed',
@@ -184,7 +184,7 @@ class MetaInfoTest extends \MailPoetTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     Subscriber::deleteMany();
   }
 }
diff --git a/tests/integration/Mailer/Methods/AmazonSESTest.php b/tests/integration/Mailer/Methods/AmazonSESTest.php
index ba71d7736d..35e5917bfd 100644
--- a/tests/integration/Mailer/Methods/AmazonSESTest.php
+++ b/tests/integration/Mailer/Methods/AmazonSESTest.php
@@ -9,7 +9,7 @@ use MailPoet\Mailer\Methods\Common\BlacklistCheck;
 use MailPoet\Mailer\Methods\ErrorMappers\AmazonSESMapper;
 
 class AmazonSESTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = [
       'method' => 'AmazonSES',
@@ -56,7 +56,7 @@ class AmazonSESTest extends \MailPoetTest {
     ];
   }
 
-  function testItsConstructorWorks() {
+  public function testItsConstructorWorks() {
     expect($this->mailer->aws_endpoint)
       ->equals(
         sprintf('email.%s.amazonaws.com', $this->settings['region'])
@@ -69,7 +69,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect(preg_match('!^\d{8}$!', $this->mailer->date_without_time))->equals(1);
   }
 
-  function testWhenReturnPathIsNullItIsSetToSenderEmail() {
+  public function testWhenReturnPathIsNullItIsSetToSenderEmail() {
     $mailer = new AmazonSES(
       $this->settings['region'],
       $this->settings['access_key'],
@@ -82,7 +82,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect($mailer->return_path)->equals($this->sender['from_email']);
   }
 
-  function testItChecksForValidRegion() {
+  public function testItChecksForValidRegion() {
     try {
       $mailer = new AmazonSES(
         'random_region',
@@ -99,7 +99,7 @@ class AmazonSESTest extends \MailPoetTest {
     }
   }
 
-  function testItCanGenerateBody() {
+  public function testItCanGenerateBody() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     expect($body['Action'])->equals('SendRawEmail');
     expect($body['Version'])->equals('2010-12-01');
@@ -108,7 +108,7 @@ class AmazonSESTest extends \MailPoetTest {
       ->equals($this->mailer->encodeMessage($this->mailer->message));
   }
 
-  function testItCanCreateMessage() {
+  public function testItCanCreateMessage() {
     $message = $this->mailer
       ->createMessage($this->newsletter, $this->subscriber, $this->extra_params);
     expect($message->getTo())
@@ -129,7 +129,7 @@ class AmazonSESTest extends \MailPoetTest {
       ->equals('<' . $this->extra_params['unsubscribe_url'] . '>');
   }
 
-  function testItCanCreateRequest() {
+  public function testItCanCreateRequest() {
     $request = $this->mailer->request($this->newsletter, $this->subscriber);
     // preserve the original message
     $raw_message = $this->mailer->encodeMessage($this->mailer->message);
@@ -147,7 +147,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect($request['body'])->equals(urldecode(http_build_query($body)));
   }
 
-  function testItCanCreateCanonicalRequest() {
+  public function testItCanCreateCanonicalRequest() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     $canonicalRequest = explode(
       "\n",
@@ -170,7 +170,7 @@ class AmazonSESTest extends \MailPoetTest {
       );
   }
 
-  function testItCanCreateCredentialScope() {
+  public function testItCanCreateCredentialScope() {
     $credentialScope = $this->mailer->getCredentialScope();
     expect($credentialScope)
       ->equals(
@@ -181,7 +181,7 @@ class AmazonSESTest extends \MailPoetTest {
       );
   }
 
-  function testItCanCreateStringToSign() {
+  public function testItCanCreateStringToSign() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     $credentialScope = $this->mailer->getCredentialScope();
     $canonicalRequest = $this->mailer->getCanonicalRequest($body);
@@ -201,7 +201,7 @@ class AmazonSESTest extends \MailPoetTest {
       );
   }
 
-  function testItCanSignRequest() {
+  public function testItCanSignRequest() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     $signedRequest = $this->mailer->signRequest($body);
     expect($signedRequest)
@@ -215,7 +215,7 @@ class AmazonSESTest extends \MailPoetTest {
       ->equals(1);
   }
 
-  function testItCannotSendWithoutProperAccessKey() {
+  public function testItCannotSendWithoutProperAccessKey() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->mailer->aws_access_key = 'somekey';
     $result = $this->mailer->send(
@@ -225,7 +225,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect($result['response'])->false();
   }
 
-  function testItCatchesSendingErrors() {
+  public function testItCatchesSendingErrors() {
     $invalid_subscriber = 'john.@doe.com';
     $result = $this->mailer->send(
       $this->newsletter,
@@ -236,7 +236,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('does not comply with RFC 2822');
   }
 
-  function testItChecksBlacklistBeforeSending() {
+  public function testItChecksBlacklistBeforeSending() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
@@ -253,7 +253,7 @@ class AmazonSESTest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('AmazonSES has returned an unknown error.');
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $result = $this->mailer->send(
       $this->newsletter,
diff --git a/tests/integration/Mailer/Methods/MailPoetAPITest.php b/tests/integration/Mailer/Methods/MailPoetAPITest.php
index 555aa51b13..7dfb00a732 100644
--- a/tests/integration/Mailer/Methods/MailPoetAPITest.php
+++ b/tests/integration/Mailer/Methods/MailPoetAPITest.php
@@ -13,7 +13,7 @@ use MailPoet\Services\AuthorizedEmailsController;
 use MailPoet\Services\Bridge\API;
 
 class MailPoetAPITest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = [
       'method' => 'MailPoet',
@@ -53,7 +53,7 @@ class MailPoetAPITest extends \MailPoetTest {
     ];
   }
 
-  function testItCanGenerateBodyForSingleMessage() {
+  public function testItCanGenerateBodyForSingleMessage() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     $subscriber = $this->mailer->processSubscriber($this->subscriber);
     expect($body[0]['to']['address'])->equals($subscriber['email']);
@@ -67,7 +67,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($body[0]['text'])->equals($this->newsletter['body']['text']);
   }
 
-  function testItCanGenerateBodyForMultipleMessages() {
+  public function testItCanGenerateBodyForMultipleMessages() {
     $newsletters = array_fill(0, 10, $this->newsletter);
     $subscribers = array_fill(0, 10, $this->subscriber);
     $body = $this->mailer->getBody($newsletters, $subscribers);
@@ -84,7 +84,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($body[0]['text'])->equals($this->newsletter['body']['text']);
   }
 
-  function testItCanAddExtraParametersToSingleMessage() {
+  public function testItCanAddExtraParametersToSingleMessage() {
     $extra_params = [
       'unsubscribe_url' => 'http://example.com',
       'meta' => $this->metaInfo,
@@ -94,7 +94,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($body[0]['meta'])->equals($extra_params['meta']);
   }
 
-  function testItCanAddExtraParametersToMultipleMessages() {
+  public function testItCanAddExtraParametersToMultipleMessages() {
     $newsletters = array_fill(0, 10, $this->newsletter);
     $subscribers = array_fill(0, 10, $this->subscriber);
     $extra_params = [
@@ -110,7 +110,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($body[9]['meta'])->equals($extra_params['meta'][9]);
   }
 
-  function testItCanProcessSubscriber() {
+  public function testItCanProcessSubscriber() {
     expect($this->mailer->processSubscriber('test@test.com'))
       ->equals(
         [
@@ -131,7 +131,7 @@ class MailPoetAPITest extends \MailPoetTest {
         ]);
   }
 
-  function testItWillNotSendIfApiKeyIsMarkedInvalid() {
+  public function testItWillNotSendIfApiKeyIsMarkedInvalid() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->mailer->api_key = 'someapi';
     $this->mailer->services_checker = Stub::make(
@@ -146,7 +146,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['response'])->false();
   }
 
-  function testItCannotSendWithoutProperApiKey() {
+  public function testItCannotSendWithoutProperApiKey() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->mailer->api->setKey('someapi');
     $result = $this->mailer->send(
@@ -156,7 +156,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['response'])->false();
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $result = $this->mailer->send(
       $this->newsletter,
@@ -165,7 +165,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['response'])->true();
   }
 
-  function testFormatConnectionError() {
+  public function testFormatConnectionError() {
     $this->mailer->api = Stub::makeEmpty(
       'MailPoet\Services\Bridge\API',
       ['sendMessages' => [
@@ -180,7 +180,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error']->getOperation())->equals(MailerError::OPERATION_CONNECT);
   }
 
-  function testFormatErrorNotArray() {
+  public function testFormatErrorNotArray() {
     $this->mailer->api = Stub::makeEmpty(
       'MailPoet\Services\Bridge\API',
       ['sendMessages' => [
@@ -196,7 +196,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error']->getOperation())->equals(MailerError::OPERATION_SEND);
   }
 
-  function testFormatErrorTooBig() {
+  public function testFormatErrorTooBig() {
     $this->mailer->api = Stub::makeEmpty(
       'MailPoet\Services\Bridge\API',
       ['sendMessages' => [
@@ -211,7 +211,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error'])->isInstanceOf(MailerError::class);
   }
 
-  function testFormatPayloadError() {
+  public function testFormatPayloadError() {
     $this->mailer->api = Stub::makeEmpty(
       'MailPoet\Services\Bridge\API',
       ['sendMessages' => [
@@ -227,7 +227,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error']->getOperation())->equals(MailerError::OPERATION_SEND);
   }
 
-  function testFormatPayloadErrorWithErrorMessage() {
+  public function testFormatPayloadErrorWithErrorMessage() {
     $this->mailer->api = Stub::makeEmpty(
       'MailPoet\Services\Bridge\API',
       ['sendMessages' => [
@@ -243,7 +243,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error']->getOperation())->equals(MailerError::OPERATION_SEND);
   }
 
-  function testItCallsAuthorizedEmailsValidationOnRelatedError() {
+  public function testItCallsAuthorizedEmailsValidationOnRelatedError() {
     $mailer = new MailPoet(
       $this->settings['api_key'],
       $this->sender,
@@ -263,7 +263,7 @@ class MailPoetAPITest extends \MailPoetTest {
     $mailer->send([$this->newsletter], [$this->subscriber]);
   }
 
-  function testItChecksBlacklistBeforeSendingToASingleSubscriber() {
+  public function testItChecksBlacklistBeforeSendingToASingleSubscriber() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
@@ -289,7 +289,7 @@ class MailPoetAPITest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('MailPoet has returned an unknown error.');
   }
 
-  function testItChecksBlacklistBeforeSendingToMultipleSubscribers() {
+  public function testItChecksBlacklistBeforeSendingToMultipleSubscribers() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
diff --git a/tests/integration/Mailer/Methods/PHPMailTest.php b/tests/integration/Mailer/Methods/PHPMailTest.php
index 751f81cc8c..70805d4f6f 100644
--- a/tests/integration/Mailer/Methods/PHPMailTest.php
+++ b/tests/integration/Mailer/Methods/PHPMailTest.php
@@ -9,7 +9,7 @@ use MailPoet\Mailer\Methods\ErrorMappers\PHPMailMapper;
 use MailPoet\Mailer\Methods\PHPMail;
 
 class PHPMailTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->sender = [
       'from_name' => 'Sender',
@@ -41,13 +41,13 @@ class PHPMailTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBuildMailer() {
+  public function testItCanBuildMailer() {
     $mailer = $this->mailer->buildMailer();
     expect($mailer)->isInstanceOf('PHPMailer');
     expect($mailer->Mailer)->equals('mail'); // uses PHP's mail() function
   }
 
-  function testWhenReturnPathIsNullItIsSetToSenderEmail() {
+  public function testWhenReturnPathIsNullItIsSetToSenderEmail() {
     $mailer = new PHPMail(
       $this->sender,
       $this->reply_to,
@@ -57,7 +57,7 @@ class PHPMailTest extends \MailPoetTest {
     expect($mailer->return_path)->equals($this->sender['from_email']);
   }
 
-  function testItCanConfigureMailerWithMessage() {
+  public function testItCanConfigureMailerWithMessage() {
     $mailer = $this->mailer
       ->configureMailerWithMessage($this->newsletter, $this->subscriber, $this->extra_params);
     expect($mailer->CharSet)->equals('UTF-8');
@@ -98,7 +98,7 @@ class PHPMailTest extends \MailPoetTest {
     );
   }
 
-  function testItCanConfigureMailerWithTextEmail() {
+  public function testItCanConfigureMailerWithTextEmail() {
     $mailer = $this->mailer
       ->configureMailerWithMessage([
         'subject' => 'testing local method (PHP mail)',
@@ -110,7 +110,7 @@ class PHPMailTest extends \MailPoetTest {
     expect($mailer->Body)->equals('TEXT body');
   }
 
-  function testItCanProcessSubscriber() {
+  public function testItCanProcessSubscriber() {
     expect($this->mailer->processSubscriber('test@test.com'))->equals(
       [
         'email' => 'test@test.com',
@@ -128,7 +128,7 @@ class PHPMailTest extends \MailPoetTest {
       ]);
   }
 
-  function testItChecksBlacklistBeforeSending() {
+  public function testItChecksBlacklistBeforeSending() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
@@ -145,7 +145,7 @@ class PHPMailTest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('PHPMail has returned an unknown error.');
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $result = $this->mailer->send(
       $this->newsletter,
diff --git a/tests/integration/Mailer/Methods/SMTPTest.php b/tests/integration/Mailer/Methods/SMTPTest.php
index d4f30aa1e7..a7c7fe8151 100644
--- a/tests/integration/Mailer/Methods/SMTPTest.php
+++ b/tests/integration/Mailer/Methods/SMTPTest.php
@@ -10,7 +10,7 @@ use MailPoet\Mailer\Methods\SMTP;
 use MailPoet\WP\Functions as WPFunctions;
 
 class SMTPTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = [
       'method' => 'SMTP',
@@ -63,7 +63,7 @@ class SMTPTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBuildMailer() {
+  public function testItCanBuildMailer() {
     $mailer = $this->mailer->buildMailer();
     expect($mailer->getTransport()->getHost())
       ->equals($this->settings['host']);
@@ -77,7 +77,7 @@ class SMTPTest extends \MailPoetTest {
       ->equals($this->settings['encryption']);
   }
 
-  function testWhenReturnPathIsNullItIsSetToSenderEmail() {
+  public function testWhenReturnPathIsNullItIsSetToSenderEmail() {
     $mailer = new SMTP(
       $this->settings['host'],
       $this->settings['port'],
@@ -93,7 +93,7 @@ class SMTPTest extends \MailPoetTest {
     expect($mailer->return_path)->equals($this->sender['from_email']);
   }
 
-  function testItCanCreateMessage() {
+  public function testItCanCreateMessage() {
     $message = $this->mailer
       ->createMessage($this->newsletter, $this->subscriber, $this->extra_params);
     expect($message->getTo())
@@ -114,7 +114,7 @@ class SMTPTest extends \MailPoetTest {
       ->equals('<' . $this->extra_params['unsubscribe_url'] . '>');
   }
 
-  function testItCanProcessSubscriber() {
+  public function testItCanProcessSubscriber() {
     expect($this->mailer->processSubscriber('test@test.com'))
       ->equals(['test@test.com' => '']);
     expect($this->mailer->processSubscriber('First <test@test.com>'))
@@ -123,7 +123,7 @@ class SMTPTest extends \MailPoetTest {
       ->equals(['test@test.com' => 'First Last']);
   }
 
-  function testItCantSendWithoutProperAuthentication() {
+  public function testItCantSendWithoutProperAuthentication() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->mailer->login = 'someone';
     $this->mailer->mailer = $this->mailer->buildMailer();
@@ -134,7 +134,7 @@ class SMTPTest extends \MailPoetTest {
     expect($result['response'])->false();
   }
 
-  function testItAppliesTransportFilter() {
+  public function testItAppliesTransportFilter() {
     $mailer = $this->mailer->buildMailer();
     expect($mailer->getTransport()->getStreamOptions())->isEmpty();
     (new WPFunctions)->addFilter(
@@ -162,7 +162,7 @@ class SMTPTest extends \MailPoetTest {
     );
   }
 
-  function testItAppliesTimeoutFilter() {
+  public function testItAppliesTimeoutFilter() {
     $mailer = $this->mailer->buildMailer();
     expect($mailer->getTransport()->getTimeout())->equals(\MailPoet\Mailer\Methods\SMTP::SMTP_CONNECTION_TIMEOUT);
     (new WPFunctions)->addFilter(
@@ -175,7 +175,7 @@ class SMTPTest extends \MailPoetTest {
     expect($mailer->getTransport()->getTimeout())->equals(20);
   }
 
-  function testItChecksBlacklistBeforeSending() {
+  public function testItChecksBlacklistBeforeSending() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
@@ -192,7 +192,7 @@ class SMTPTest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('SMTP has returned an unknown error.');
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $result = $this->mailer->send(
       $this->newsletter,
@@ -201,6 +201,6 @@ class SMTPTest extends \MailPoetTest {
     expect($result['response'])->true();
   }
 
-  function _after() {
+  public function _after() {
   }
 }
diff --git a/tests/integration/Mailer/Methods/SendGridTest.php b/tests/integration/Mailer/Methods/SendGridTest.php
index ee60fd6167..f1c7bc5e4b 100644
--- a/tests/integration/Mailer/Methods/SendGridTest.php
+++ b/tests/integration/Mailer/Methods/SendGridTest.php
@@ -9,7 +9,7 @@ use MailPoet\Mailer\Methods\ErrorMappers\SendGridMapper;
 use MailPoet\Mailer\Methods\SendGrid;
 
 class SendGridTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = [
       'method' => 'SendGrid',
@@ -46,7 +46,7 @@ class SendGridTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanGenerateBody() {
+  public function testItCanGenerateBody() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber, $this->extra_params);
     expect($body['to'])->contains($this->subscriber);
     expect($body['from'])->equals($this->sender['from_email']);
@@ -60,7 +60,7 @@ class SendGridTest extends \MailPoetTest {
     expect($body['text'])->equals($this->newsletter['body']['text']);
   }
 
-  function testItCanCreateRequest() {
+  public function testItCanCreateRequest() {
     $body = $this->mailer->getBody($this->newsletter, $this->subscriber);
     $request = $this->mailer->request($this->newsletter, $this->subscriber);
     expect($request['timeout'])->equals(10);
@@ -71,12 +71,12 @@ class SendGridTest extends \MailPoetTest {
     expect($request['body'])->equals(http_build_query($body));
   }
 
-  function testItCanDoBasicAuth() {
+  public function testItCanDoBasicAuth() {
     expect($this->mailer->auth())
       ->equals('Bearer ' . $this->settings['api_key']);
   }
 
-  function testItCannotSendWithoutProperApiKey() {
+  public function testItCannotSendWithoutProperApiKey() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $this->mailer->api_key = 'someapi';
     $result = $this->mailer->send(
@@ -86,7 +86,7 @@ class SendGridTest extends \MailPoetTest {
     expect($result['response'])->false();
   }
 
-  function testItChecksBlacklistBeforeSending() {
+  public function testItChecksBlacklistBeforeSending() {
     $blacklisted_subscriber = 'blacklist_test@example.com';
     $blacklist = Stub::make(new BlacklistCheck(), ['isBlacklisted' => true], $this);
     $mailer = Stub::make(
@@ -103,7 +103,7 @@ class SendGridTest extends \MailPoetTest {
     expect($result['error']->getMessage())->contains('SendGrid has returned an unknown error.');
   }
 
-  function testItCanSend() {
+  public function testItCanSend() {
     if (getenv('WP_TEST_MAILER_ENABLE_SENDING') !== 'true') $this->markTestSkipped();
     $result = $this->mailer->send(
       $this->newsletter,
diff --git a/tests/integration/Mailer/WordPress/WordpressMailerTest.php b/tests/integration/Mailer/WordPress/WordpressMailerTest.php
index 9bd3852448..837de2c952 100644
--- a/tests/integration/Mailer/WordPress/WordpressMailerTest.php
+++ b/tests/integration/Mailer/WordPress/WordpressMailerTest.php
@@ -12,12 +12,12 @@ class WordpressMailerTest extends \MailPoetTest {
   /** @var SubscribersRepository */
   private $subscribers_repository;
 
-  function _before() {
+  public function _before() {
     $this->subscribers_repository = $this->di_container->get(SubscribersRepository::class);
     $this->subscribers_repository->truncate();
   }
 
-  function testItdoesNotSendWhenPreSendCheckFails() {
+  public function testItdoesNotSendWhenPreSendCheckFails() {
     $mailer = $this->createMock(Mailer::class);
     $mailer->expects($this->never())->method('send');
     $fallback_mailer = $this->createMock(FallbackMailer::class);
@@ -28,7 +28,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function testItFormatsTextNewsletterForMailer() {
+  public function testItFormatsTextNewsletterForMailer() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -51,7 +51,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function testItFormatsSubscriberForMailer() {
+  public function testItFormatsSubscriberForMailer() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -72,7 +72,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function testItFormatsHtmlNewsletterForMailer() {
+  public function testItFormatsHtmlNewsletterForMailer() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -96,7 +96,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function testItReturnsOnSuccess() {
+  public function testItReturnsOnSuccess() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -111,7 +111,7 @@ class WordpressMailerTest extends \MailPoetTest {
     expect($wpMailer->send())->true();
   }
 
-  function testItUsesBackupMailerWhenPrimaryFails() {
+  public function testItUsesBackupMailerWhenPrimaryFails() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -130,7 +130,7 @@ class WordpressMailerTest extends \MailPoetTest {
     expect($wpMailer->send())->true();
   }
 
-  function testItThrowsOnError() {
+  public function testItThrowsOnError() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -157,7 +157,7 @@ class WordpressMailerTest extends \MailPoetTest {
     expect($error_message)->same('Error from primary mailer');
   }
 
-  function testItThrowsOnUnknownContentType() {
+  public function testItThrowsOnUnknownContentType() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->never())
@@ -173,7 +173,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function testItTranslateExeceptionsToPhpmailerException() {
+  public function testItTranslateExeceptionsToPhpmailerException() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -200,7 +200,7 @@ class WordpressMailerTest extends \MailPoetTest {
     expect($error_message)->same('Exception from primary mailer');
   }
 
-  function testItAddSubscriberMetaInfo() {
+  public function testItAddSubscriberMetaInfo() {
     $mailer = $this->createMock(Mailer::class);
     $mailer
       ->expects($this->once())
@@ -230,7 +230,7 @@ class WordpressMailerTest extends \MailPoetTest {
     $wpMailer->send();
   }
 
-  function _after() {
+  public function _after() {
     $this->subscribers_repository->truncate();
   }
 }
diff --git a/tests/integration/Models/CustomFieldTest.php b/tests/integration/Models/CustomFieldTest.php
index b026a60f32..4cd815bad4 100644
--- a/tests/integration/Models/CustomFieldTest.php
+++ b/tests/integration/Models/CustomFieldTest.php
@@ -7,7 +7,7 @@ use MailPoet\Models\Subscriber;
 use MailPoet\Models\SubscriberCustomField;
 
 class CustomFieldTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->data = [
       'name' => 'City',
@@ -32,12 +32,12 @@ class CustomFieldTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->custom_field->id() > 0)->true();
     expect($this->custom_field->getErrors())->false();
   }
 
-  function testItCanBeUpdated() {
+  public function testItCanBeUpdated() {
     expect($this->custom_field->name)->equals($this->data['name']);
 
     $updated_custom_field = CustomField::createOrUpdate([
@@ -50,25 +50,25 @@ class CustomFieldTest extends \MailPoetTest {
     expect($updated_custom_field->id)->equals($this->custom_field->id);
   }
 
-  function testItHasAName() {
+  public function testItHasAName() {
     expect($this->custom_field->name)->equals($this->data['name']);
   }
 
-  function testItHasAType() {
+  public function testItHasAType() {
     expect($this->custom_field->type)->equals($this->data['type']);
   }
 
-  function testItHasSerializedParams() {
+  public function testItHasSerializedParams() {
     $params = unserialize($this->custom_field->params);
     expect($params)->equals($this->data['params']);
   }
 
-  function testItCanDecodeParams() {
+  public function testItCanDecodeParams() {
     $custom_field = $this->custom_field->asArray();
     expect($custom_field['params'])->equals($this->data['params']);
   }
 
-  function testItHasToBeValid() {
+  public function testItHasToBeValid() {
     $invalid_custom_field = CustomField::create();
 
     $result = $invalid_custom_field->save();
@@ -79,18 +79,18 @@ class CustomFieldTest extends \MailPoetTest {
     expect($errors[1])->equals('Please specify a type.');
   }
 
-  function testItHasACreatedAtOnCreation() {
+  public function testItHasACreatedAtOnCreation() {
     $custom_field = CustomField::findOne($this->custom_field->id);
     expect($custom_field->created_at)->notNull();
   }
 
-  function testItHasAnUpdatedAtOnCreation() {
+  public function testItHasAnUpdatedAtOnCreation() {
     $custom_field = CustomField::findOne($this->custom_field->id);
     expect($custom_field->updated_at)
       ->equals($custom_field->created_at);
   }
 
-  function testItUpdatesTheUpdatedAtOnUpdate() {
+  public function testItUpdatesTheUpdatedAtOnUpdate() {
     $custom_field = CustomField::findOne($this->custom_field->id);
     $created_at = $custom_field->created_at;
 
@@ -107,7 +107,7 @@ class CustomFieldTest extends \MailPoetTest {
     expect($is_time_updated)->true();
   }
 
-  function testItCanHaveManySubscribers() {
+  public function testItCanHaveManySubscribers() {
     foreach ($this->subscribers as $subscriber) {
       $subscriber = Subscriber::createOrUpdate($subscriber);
 
@@ -122,7 +122,7 @@ class CustomFieldTest extends \MailPoetTest {
     expect(count($subscribers))->equals(2);
   }
 
-  function testItCanHaveAValue() {
+  public function testItCanHaveAValue() {
     $subscriber = Subscriber::createOrUpdate($this->subscribers[0]);
 
     $association = SubscriberCustomField::create();
@@ -135,7 +135,7 @@ class CustomFieldTest extends \MailPoetTest {
     expect($subscriber->value)->equals($association->value);
   }
 
-  function _after() {
+  public function _after() {
     CustomField::deleteMany();
     Subscriber::deleteMany();
     SubscriberCustomField::deleteMany();
diff --git a/tests/integration/Models/FormTest.php b/tests/integration/Models/FormTest.php
index e4f5bf73a6..56128e9d0e 100644
--- a/tests/integration/Models/FormTest.php
+++ b/tests/integration/Models/FormTest.php
@@ -9,7 +9,7 @@ class FormTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->form = Form::createOrUpdate([
@@ -17,12 +17,12 @@ class FormTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->form->id() > 0)->true();
     expect($this->form->getErrors())->false();
   }
 
-  function testItCanBeGrouped() {
+  public function testItCanBeGrouped() {
     $forms = Form::filter('groupBy', 'all')->findArray();
     expect($forms)->count(1);
 
@@ -41,23 +41,23 @@ class FormTest extends \MailPoetTest {
     expect($forms)->count(1);
   }
 
-  function testItCanBeSearched() {
+  public function testItCanBeSearched() {
     $form = Form::filter('search', 'my F')->findOne();
     expect($form->name)->equals('My Form');
   }
 
-  function testItHasACreatedAtOnCreation() {
+  public function testItHasACreatedAtOnCreation() {
     $form = Form::findOne($this->form->id);
     expect($form->created_at)->notNull();
   }
 
-  function testItHasAnUpdatedAtOnCreation() {
+  public function testItHasAnUpdatedAtOnCreation() {
     $form = Form::findOne($this->form->id);
     expect($form->updated_at)
       ->equals($form->created_at);
   }
 
-  function testItUpdatesTheUpdatedAtOnUpdate() {
+  public function testItUpdatesTheUpdatedAtOnUpdate() {
     $form = Form::findOne($this->form->id);
     $created_at = $form->created_at;
 
@@ -74,7 +74,7 @@ class FormTest extends \MailPoetTest {
     expect($is_time_updated)->true();
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     $created_form = Form::createOrUpdate([
       'name' => 'Created Form',
     ]);
@@ -92,7 +92,7 @@ class FormTest extends \MailPoetTest {
     expect($form->name)->equals('Updated Form');
   }
 
-  function testItCanProvideAFieldList() {
+  public function testItCanProvideAFieldList() {
     $form = Form::createOrUpdate([
       'name' => 'My Form',
       'body' => [
@@ -113,7 +113,7 @@ class FormTest extends \MailPoetTest {
     expect($form->getFieldList())->equals(['email', 'cf_2']);
   }
 
-  function testItUpdatesSuccessMessagesWhenConfirmationIsDisabled() {
+  public function testItUpdatesSuccessMessagesWhenConfirmationIsDisabled() {
     $default = Form::createOrUpdate([
       'name' => 'with default message',
       'settings' => ['success_message' => 'Check your inbox or spam folder to confirm your subscription.'],
@@ -130,7 +130,7 @@ class FormTest extends \MailPoetTest {
     expect($custom['settings']['success_message'])->equals('Thanks for joining us!');
   }
 
-  function testItUpdatesSuccessMessagesWhenConfirmationIsEnabled() {
+  public function testItUpdatesSuccessMessagesWhenConfirmationIsEnabled() {
     $default = Form::createOrUpdate([
       'name' => 'with default message',
       'settings' => ['success_message' => 'Check your inbox or spam folder to confirm your subscription.'],
@@ -147,7 +147,7 @@ class FormTest extends \MailPoetTest {
     expect($custom['settings']['success_message'])->equals('Thanks for joining us!');
   }
 
-  function _after() {
+  public function _after() {
     Form::deleteMany();
   }
 }
diff --git a/tests/integration/Models/ModelTest.php b/tests/integration/Models/ModelTest.php
index 9b019d6b6e..2f2b4f69e8 100644
--- a/tests/integration/Models/ModelTest.php
+++ b/tests/integration/Models/ModelTest.php
@@ -7,7 +7,7 @@ use MailPoet\Models\Model as MPModel;
 use MailPoetVendor\Idiorm\ORM;
 
 class ModelTest extends \MailPoetTest {
-  function testItRethrowsPDOExceptions() {
+  public function testItRethrowsPDOExceptions() {
     $message = 'Error message';
     $model = Stub::make('MailPoet\Models\Model');
     $pdo = Stub::make(
@@ -28,7 +28,7 @@ class ModelTest extends \MailPoetTest {
     }
   }
 
-  function testItConvertsModelObjectToArray() {
+  public function testItConvertsModelObjectToArray() {
     $model = MPModel::create();
     $model->first = 'first';
     $model->last = 'last';
@@ -45,28 +45,28 @@ class ModelTest extends \MailPoetTest {
     );
   }
 
-  function testSetErrorsWithoutCode() {
+  public function testSetErrorsWithoutCode() {
     $model = MPModel::create();
     $model->setError('error1');
     $model->setError('error2');
     expect($model->getErrors())->equals(['error1', 'error2']);
   }
 
-  function testSetErrorsAsArray() {
+  public function testSetErrorsAsArray() {
     $model = MPModel::create();
     $model->setError(['error1']);
     $model->setError(['error2', 'error1']);
     expect($model->getErrors())->equals(['error1', 'error2']);
   }
 
-  function testSetErrorsWithCode() {
+  public function testSetErrorsWithCode() {
     $model = MPModel::create();
     $model->setError('error1');
     $model->setError('error2', 5);
     expect($model->getErrors())->equals(['error1', 5 => 'error2']);
   }
 
-  function testSetErrorCodeForDuplicateRecords() {
+  public function testSetErrorCodeForDuplicateRecords() {
     $orm = Stub::makeEmpty(
       ORM::class,
       [
@@ -85,7 +85,7 @@ class ModelTest extends \MailPoetTest {
     expect($errors[MPModel::DUPLICATE_RECORD])->contains('Please specify a different "name".');
   }
 
-  function _after() {
+  public function _after() {
     ORM::setDb($this->connection->getWrappedConnection());
   }
 }
diff --git a/tests/integration/Models/ModelValidatorTest.php b/tests/integration/Models/ModelValidatorTest.php
index 17b9cd506e..6a7a7c6942 100644
--- a/tests/integration/Models/ModelValidatorTest.php
+++ b/tests/integration/Models/ModelValidatorTest.php
@@ -7,19 +7,19 @@ use MailPoet\Models\ModelValidator;
 class ModelValidatorTest extends \MailPoetTest {
   public $validator;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->validator = new ModelValidator();
   }
 
-  function testItConfiguresValidators() {
+  public function testItConfiguresValidators() {
     $configured_validators = $this->validator->getValidators();
     foreach (array_keys($this->validator->validators) as $validator) {
       expect($configured_validators)->contains($validator);
     }
   }
 
-  function testItValidatesEmail() {
+  public function testItValidatesEmail() {
     expect($this->validator->validateEmail('test'))->false();
     expect($this->validator->validateEmail('tést@éxample.com'))->false();
     expect($this->validator->validateEmail('test@example.com'))->true();
@@ -27,13 +27,13 @@ class ModelValidatorTest extends \MailPoetTest {
     expect($this->validator->validateEmail('a@b.c'))->false();
   }
 
-  function testItValidatesNonRoleEmail() {
+  public function testItValidatesNonRoleEmail() {
     expect($this->validator->validateNonRoleEmail('test'))->false();
     expect($this->validator->validateNonRoleEmail('webmaster@example.com'))->false();
     expect($this->validator->validateNonRoleEmail('test@example.com'))->true();
   }
 
-  function testItValidatesRenderedNewsletterBody() {
+  public function testItValidatesRenderedNewsletterBody() {
     expect($this->validator->validateRenderedNewsletterBody('test'))->false();
     expect($this->validator->validateRenderedNewsletterBody(serialize('test')))->false();
     expect($this->validator->validateRenderedNewsletterBody(['html' => 'test', 'text' => null]))->false();
diff --git a/tests/integration/Models/NewsletterOptionFieldTest.php b/tests/integration/Models/NewsletterOptionFieldTest.php
index 31bc507709..8754f2b31c 100644
--- a/tests/integration/Models/NewsletterOptionFieldTest.php
+++ b/tests/integration/Models/NewsletterOptionFieldTest.php
@@ -8,7 +8,7 @@ use MailPoet\Models\NewsletterOptionField;
 use MailPoetVendor\Idiorm\ORM;
 
 class NewsletterOptionFieldTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->data = [
       'name' => 'event',
@@ -36,21 +36,21 @@ class NewsletterOptionFieldTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->option_field->id() > 0)->equals(true);
     expect($this->option_field->getErrors())->false();
   }
 
-  function testItHasName() {
+  public function testItHasName() {
     expect($this->option_field->name)->equals($this->data['name']);
   }
 
-  function testItHasNewsletterType() {
+  public function testItHasNewsletterType() {
     expect($this->option_field->newsletter_type)
       ->equals($this->data['newsletter_type']);
   }
 
-  function testItHasToBeValid() {
+  public function testItHasToBeValid() {
     $invalid_newsletter_option = NewsletterOptionField::create();
     $result = $invalid_newsletter_option->save();
     $errors = $result->getErrors();
@@ -60,17 +60,17 @@ class NewsletterOptionFieldTest extends \MailPoetTest {
     expect($errors[1])->equals('Please specify a newsletter type.');
   }
 
-  function testItHasACreatedAtOnCreation() {
+  public function testItHasACreatedAtOnCreation() {
     expect($this->option_field->created_at)->notNull();
   }
 
-  function testItHasAnUpdatedAtOnCreation() {
+  public function testItHasAnUpdatedAtOnCreation() {
     $option_field = NewsletterOptionField::findOne($this->option_field->id);
     expect($option_field->updated_at)
       ->equals($option_field->created_at);
   }
 
-  function testItUpdatesTheUpdatedAtOnUpdate() {
+  public function testItUpdatesTheUpdatedAtOnUpdate() {
     $option_field = NewsletterOptionField::findOne($this->option_field->id);
     $created_at = $option_field->created_at;
 
@@ -86,7 +86,7 @@ class NewsletterOptionFieldTest extends \MailPoetTest {
     expect($is_time_updated)->true();
   }
 
-  function testItCanHaveManyNewsletters() {
+  public function testItCanHaveManyNewsletters() {
     foreach ($this->newsletter_data as $data) {
       $newsletter = Newsletter::create();
       $newsletter->hydrate($data);
@@ -102,7 +102,7 @@ class NewsletterOptionFieldTest extends \MailPoetTest {
     expect(count($newsletters))->equals(2);
   }
 
-  function testItCanStoreOptionValue() {
+  public function testItCanStoreOptionValue() {
     $newsletter = Newsletter::create();
     $newsletter->hydrate($this->newsletter_data[0]);
     $newsletter->save();
@@ -117,7 +117,7 @@ class NewsletterOptionFieldTest extends \MailPoetTest {
     expect($newsletter->value)->equals($association->value);
   }
 
-  function _after() {
+  public function _after() {
     ORM::forTable(NewsletterOption::$_table)
       ->deleteMany();
     ORM::forTable(NewsletterOptionField::$_table)
diff --git a/tests/integration/Models/NewsletterOptionTest.php b/tests/integration/Models/NewsletterOptionTest.php
index fe921831a4..d036fd0d20 100644
--- a/tests/integration/Models/NewsletterOptionTest.php
+++ b/tests/integration/Models/NewsletterOptionTest.php
@@ -8,7 +8,7 @@ use MailPoetVendor\Idiorm\ORM;
 class NewsletterOptionTest extends \MailPoetTest {
   public $data;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->data = [
       'newsletter_id' => 1,
@@ -17,7 +17,7 @@ class NewsletterOptionTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanCreateOrUpdateNewsletterOptionFieldRelation() {
+  public function testItCanCreateOrUpdateNewsletterOptionFieldRelation() {
     // it can create
     $data = $this->data;
     NewsletterOption::createOrUpdate($data);
@@ -36,7 +36,7 @@ class NewsletterOptionTest extends \MailPoetTest {
   }
 
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
   }
 }
diff --git a/tests/integration/Models/NewsletterPostTest.php b/tests/integration/Models/NewsletterPostTest.php
index bb03ec8c9c..0684b0e330 100644
--- a/tests/integration/Models/NewsletterPostTest.php
+++ b/tests/integration/Models/NewsletterPostTest.php
@@ -7,7 +7,7 @@ use MailPoetVendor\Carbon\Carbon;
 use MailPoetVendor\Idiorm\ORM;
 
 class NewsletterPostTest extends \MailPoetTest {
-  function testItCanGetLatestNewsletterPost() {
+  public function testItCanGetLatestNewsletterPost() {
     foreach (range(1, 5) as $index) {
       $newsletter_post = NewsletterPost::create();
       $newsletter_post->newsletter_id = 1;
@@ -21,7 +21,7 @@ class NewsletterPostTest extends \MailPoetTest {
     expect($latest_newsletter_post->post_id)->equals(5);
   }
 
-  function _after() {
+  public function _after() {
     ORM::for_table(NewsletterPost::$_table)
       ->deleteMany();
   }
diff --git a/tests/integration/Models/NewsletterTemplateTest.php b/tests/integration/Models/NewsletterTemplateTest.php
index ba34b1dbc8..7aaf76f94b 100644
--- a/tests/integration/Models/NewsletterTemplateTest.php
+++ b/tests/integration/Models/NewsletterTemplateTest.php
@@ -6,7 +6,7 @@ use MailPoet\Models\NewsletterTemplate;
 use MailPoetVendor\Idiorm\ORM;
 
 class NewsletterTemplateTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->data = [
       'name' => 'Some template',
@@ -18,12 +18,12 @@ class NewsletterTemplateTest extends \MailPoetTest {
     $this->saved = $template->save();
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->saved->id() > 0)->true();
     expect($this->saved->getErrors())->false();
   }
 
-  function testItHasToBeValid() {
+  public function testItHasToBeValid() {
     $invalid_newsletter_template = NewsletterTemplate::create();
     $result = $invalid_newsletter_template->save();
     $errors = $result->getErrors();
@@ -33,19 +33,19 @@ class NewsletterTemplateTest extends \MailPoetTest {
     expect($errors[1])->equals('The template body cannot be empty.');
   }
 
-  function testItHasName() {
+  public function testItHasName() {
     $template = NewsletterTemplate::where('name', $this->data['name'])
       ->findOne();
     expect($template->name)->equals($this->data['name']);
   }
 
-  function testItHasBody() {
+  public function testItHasBody() {
     $template = NewsletterTemplate::where('body', $this->data['body'])
       ->findOne();
     expect($template->body)->equals($this->data['body']);
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     $created_template = NewsletterTemplate::createOrUpdate(
       [
         'name' => 'Another template',
@@ -71,7 +71,7 @@ class NewsletterTemplateTest extends \MailPoetTest {
     expect($template->name)->equals('Another template updated');
   }
 
-  function testItCanCleanRecentlySent() {
+  public function testItCanCleanRecentlySent() {
     $total = NewsletterTemplate::RECENTLY_SENT_COUNT + 5;
     for ($i = 0; $i < $total; $i++) {
       NewsletterTemplate::createOrUpdate([
@@ -101,7 +101,7 @@ class NewsletterTemplateTest extends \MailPoetTest {
     expect($first->name)->equals('Testing template 5');
   }
 
-  function _after() {
+  public function _after() {
     ORM::for_table(NewsletterTemplate::$_table)
       ->deleteMany();
   }
diff --git a/tests/integration/Models/NewsletterTest.php b/tests/integration/Models/NewsletterTest.php
index b57a906286..11b978ada5 100644
--- a/tests/integration/Models/NewsletterTest.php
+++ b/tests/integration/Models/NewsletterTest.php
@@ -20,7 +20,7 @@ use MailPoetVendor\Carbon\Carbon;
 use MailPoetVendor\Idiorm\ORM;
 
 class NewsletterTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter = Newsletter::createOrUpdate([
       'subject' => 'My Standard Newsletter',
@@ -49,43 +49,43 @@ class NewsletterTest extends \MailPoetTest {
     $this->sending_queue->save();
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->newsletter->id() > 0)->true();
     expect($this->newsletter->getErrors())->false();
   }
 
-  function testItHasASubject() {
+  public function testItHasASubject() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->subject)->equals($this->newsletter->subject);
   }
 
-  function testItHasAType() {
+  public function testItHasAType() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->type)->equals($this->newsletter->type);
   }
 
-  function testItHasABody() {
+  public function testItHasABody() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->body)->equals($this->newsletter->body);
   }
 
-  function testItHasPreheader() {
+  public function testItHasPreheader() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->preheader)->equals($this->newsletter->preheader);
   }
 
-  function testItHasACreatedAtOnCreation() {
+  public function testItHasACreatedAtOnCreation() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->created_at)->notNull();
   }
 
-  function testItHasAnUpdatedAtOnCreation() {
+  public function testItHasAnUpdatedAtOnCreation() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     expect($newsletter->updated_at)
       ->equals($newsletter->created_at);
   }
 
-  function testItUpdatesTheUpdatedAtOnUpdate() {
+  public function testItUpdatesTheUpdatedAtOnUpdate() {
     $newsletter = Newsletter::findOne($this->newsletter->id);
     $created_at = $newsletter->created_at;
 
@@ -102,13 +102,13 @@ class NewsletterTest extends \MailPoetTest {
     expect($is_time_updated)->true();
   }
 
-  function testItCanBeQueued() {
+  public function testItCanBeQueued() {
     $queue = $this->newsletter->getQueue();
     expect($queue->id > 0)->true();
     expect($queue->newsletter_id)->equals($this->newsletter->id);
   }
 
-  function testItCanHaveSegments() {
+  public function testItCanHaveSegments() {
     $newsletter_segments = $this->newsletter->segments()->findArray();
     expect($newsletter_segments)->count(2);
     expect($newsletter_segments[0]['id'])->equals($this->segment_1->id);
@@ -117,7 +117,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter_segments[1]['name'])->equals('Segment 2');
   }
 
-  function testItCanHaveParentNewsletter() {
+  public function testItCanHaveParentNewsletter() {
     $parent_newsletter = Newsletter::create();
     $parent_newsletter->type = Newsletter::TYPE_NOTIFICATION;
     $parent_newsletter->save();
@@ -130,7 +130,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($parent->id)->equals($parent_newsletter->id);
   }
 
-  function testItCanHaveDeletedSegments() {
+  public function testItCanHaveDeletedSegments() {
     $this->segment_2->delete();
     $this->newsletter->withSegments(true);
     $newsletter_segments = $this->newsletter->segments;
@@ -141,7 +141,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter_segments[1]['name'])->contains('Deleted');
   }
 
-  function testItCanHaveStatistics() {
+  public function testItCanHaveStatistics() {
     $newsletter = $this->newsletter;
     $sending_queue = $this->sending_queue;
 
@@ -178,7 +178,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($statistics['unsubscribed'])->equals(1);
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     $is_created = Newsletter::createOrUpdate(
       [
         'subject' => 'new newsletter',
@@ -201,13 +201,13 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter->subject)->equals('updated newsletter');
   }
 
-  function testItCannotSetAnEmptyDeletedAt() {
+  public function testItCannotSetAnEmptyDeletedAt() {
     $this->newsletter->deleted_at = '';
     $newsletter = $this->newsletter->save();
     expect($newsletter->deleted_at)->equals('NULL');
   }
 
-  function testItCanBeFilteredBySegment() {
+  public function testItCanBeFilteredBySegment() {
     // no filter
     $newsletters = Newsletter::filter('filterBy')->findArray();
     expect($newsletters)->count(1);
@@ -233,7 +233,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletters)->isEmpty();
   }
 
-  function testItCanBeGrouped() {
+  public function testItCanBeGrouped() {
     $newsletters = Newsletter::filter('groupBy', [
       'group' => 'all',
     ])->findArray();
@@ -262,7 +262,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletters)->count(1);
   }
 
-  function testItHasSearchFilter() {
+  public function testItHasSearchFilter() {
     Newsletter::createOrUpdate(
       [
         'subject' => 'search for "pineapple"',
@@ -274,7 +274,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter->subject)->contains('pineapple');
   }
 
-  function testItCanHaveOptions() {
+  public function testItCanHaveOptions() {
     $newsletter_options = [
       'name' => 'Event',
       'newsletter_type' => Newsletter::TYPE_WELCOME,
@@ -292,7 +292,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter->Event)->equals($association->value);
   }
 
-  function testItGetsArchiveNewslettersForSegments() {
+  public function testItGetsArchiveNewslettersForSegments() {
     // clear the DB
     $this->_after();
 
@@ -330,7 +330,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($results[0]->type)->equals(Newsletter::TYPE_NOTIFICATION_HISTORY);
   }
 
-  function testItGetsAllArchiveNewsletters() {
+  public function testItGetsAllArchiveNewsletters() {
     // clear the DB
     $this->_after();
 
@@ -379,23 +379,23 @@ class NewsletterTest extends \MailPoetTest {
     expect($results[1]->type)->equals(Newsletter::TYPE_NOTIFICATION_HISTORY);
   }
 
-  function testItGeneratesHashOnNewsletterSave() {
+  public function testItGeneratesHashOnNewsletterSave() {
     expect(strlen($this->newsletter->hash))
       ->equals(Security::HASH_LENGTH);
   }
 
-  function testItRegeneratesHashOnNotificationHistoryCreation() {
+  public function testItRegeneratesHashOnNotificationHistoryCreation() {
     $notification_history = $this->newsletter->createNotificationHistory();
     expect($notification_history->hash)->notEquals($this->newsletter->hash);
     expect(strlen($notification_history->hash))
       ->equals(Security::HASH_LENGTH);
   }
 
-  function testItGetsQueueFromNewsletter() {
+  public function testItGetsQueueFromNewsletter() {
     expect($this->newsletter->queue()->findOne()->id)->equals($this->sending_queue->id);
   }
 
-  function testItCanBeRestored() {
+  public function testItCanBeRestored() {
     $this->newsletter->status = Newsletter::STATUS_SENT;
     $this->newsletter->trash();
     expect($this->newsletter->deleted_at)->notNull();
@@ -411,7 +411,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($this->newsletter->status)->equals(Newsletter::STATUS_DRAFT);
   }
 
-  function testItCanBulkRestoreNewsletters() {
+  public function testItCanBulkRestoreNewsletters() {
     $statuses = [
       Newsletter::STATUS_DRAFT,
       Newsletter::STATUS_SENT,
@@ -439,7 +439,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(Newsletter::where('status', Newsletter::STATUS_SENDING)->findArray())->count(0);
   }
 
-  function testItDeletesSegmentAndQueueAssociationsWhenNewsletterIsDeleted() {
+  public function testItDeletesSegmentAndQueueAssociationsWhenNewsletterIsDeleted() {
     $newsletter = $this->newsletter;
 
     // create multiple sending queues
@@ -461,7 +461,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter_segments)->isEmpty();
   }
 
-  function testItDeletesChildrenSegmentAndQueueAssociationsWhenParentNewsletterIsDeleted() {
+  public function testItDeletesChildrenSegmentAndQueueAssociationsWhenParentNewsletterIsDeleted() {
     $parent_newsletter = $this->newsletter;
     // create multiple children (post notification history) newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
@@ -494,7 +494,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(NewsletterSegment::findArray())->count(0);
   }
 
-  function testItTrashesQueueAssociationsWhenNewsletterIsTrashed() {
+  public function testItTrashesQueueAssociationsWhenNewsletterIsTrashed() {
     // create multiple sending queues
     $newsletter = $this->newsletter;
     for ($i = 1; $i <= 5; $i++) {
@@ -510,7 +510,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNotNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItTrashesChildrenQueueAssociationsWhenParentNewsletterIsTrashed() {
+  public function testItTrashesChildrenQueueAssociationsWhenParentNewsletterIsTrashed() {
     $parent_newsletter = $this->newsletter;
     // create multiple children (post notification history) newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
@@ -536,7 +536,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNotNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItRestoresTrashedQueueAssociationsWhenNewsletterIsRestored() {
+  public function testItRestoresTrashedQueueAssociationsWhenNewsletterIsRestored() {
     // create multiple sending queues
     $newsletter = $this->newsletter;
     for ($i = 1; $i <= 5; $i++) {
@@ -553,7 +553,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItRestoresTrashedChildrenQueueAssociationsWhenParentNewsletterIsRestored() {
+  public function testItRestoresTrashedChildrenQueueAssociationsWhenParentNewsletterIsRestored() {
     // delete parent newsletter and sending queue
     $parent_newsletter = $this->newsletter;
     $parent_newsletter->deleted_at = date('Y-m-d H:i:s');
@@ -588,7 +588,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItTrashesAllQueueAssociationsWhenNewslettersAreBulkTrashed() {
+  public function testItTrashesAllQueueAssociationsWhenNewslettersAreBulkTrashed() {
     // create multiple newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
       $newsletter = Newsletter::createOrUpdate(
@@ -611,7 +611,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNotNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItTrashesAllChildrenQueueAssociationsWhenParentNewslettersAreBulkTrashed() {
+  public function testItTrashesAllChildrenQueueAssociationsWhenParentNewslettersAreBulkTrashed() {
     // create multiple children (post notification history) newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
       $newsletter = Newsletter::createOrUpdate(
@@ -635,7 +635,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNotNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItBulkRestoresTrashedQueueAssociationsWhenNewslettersAreBulkRestored() {
+  public function testItBulkRestoresTrashedQueueAssociationsWhenNewslettersAreBulkRestored() {
     // create multiple newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
       $newsletter = Newsletter::createOrUpdate(
@@ -660,7 +660,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItBulkRestoresTrashedChildrenQueueAssociationsWhenParentNewslettersAreBulkRestored() {
+  public function testItBulkRestoresTrashedChildrenQueueAssociationsWhenParentNewslettersAreBulkRestored() {
     // create multiple children (post notification history) newsletters and sending queues
     for ($i = 1; $i <= 5; $i++) {
       $newsletter = Newsletter::createOrUpdate(
@@ -686,7 +686,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(SendingQueue::whereNull('deleted_at')->findArray())->count(6);
   }
 
-  function testItBulkDeletesSegmentAndQueueAssociationsWhenNewslettersAreBulkDeleted() {
+  public function testItBulkDeletesSegmentAndQueueAssociationsWhenNewslettersAreBulkDeleted() {
     // create multiple newsletters, sending queues and newsletter segments
     for ($i = 1; $i <= 5; $i++) {
       $newsletter = Newsletter::createOrUpdate(
@@ -716,7 +716,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(NewsletterSegment::findArray())->count(0);
   }
 
-  function testItBulkDeletesChildrenSegmentAndQueueAssociationsWhenParentNewslettersAreBulkDeleted() {
+  public function testItBulkDeletesChildrenSegmentAndQueueAssociationsWhenParentNewslettersAreBulkDeleted() {
     $this->_after();
     // create multiple children (post notification history) newsletters, sending queues and newsletter segments
     for ($i = 1; $i <= 5; $i++) {
@@ -747,7 +747,7 @@ class NewsletterTest extends \MailPoetTest {
     expect(NewsletterSegment::findArray())->count(0);
   }
 
-  function testItDuplicatesNewsletter() {
+  public function testItDuplicatesNewsletter() {
     $original_newsletter = $this->newsletter;
     $original_newsletter->status = Newsletter::STATUS_SENT;
     $original_newsletter->sent_at = $original_newsletter->deleted_at = $original_newsletter->created_at = $original_newsletter->updated_at = date( '2000-m-d H:i:s');
@@ -771,7 +771,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($duplicate_newsletter->subject)->equals($data['subject']);
   }
 
-  function testItCanQueryAutomaticEmailsByGroup() {
+  public function testItCanQueryAutomaticEmailsByGroup() {
     $newsletter_1 = Newsletter::createOrUpdate(
       [
         'subject' => 'WooCommerce',
@@ -844,7 +844,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($result[1]->id)->equals($newsletter_2->id);
   }
 
-  function testItGetsAndDecodesNewsletterOptionMetaField() {
+  public function testItGetsAndDecodesNewsletterOptionMetaField() {
     $newsletter = Newsletter::createOrUpdate(
       [
         'subject' => 'Test Option Meta Field',
@@ -879,7 +879,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter->getMeta())->equals($meta);
   }
 
-  function testPausesTaskWhenNewsletterWithActivationIsDisabled() {
+  public function testPausesTaskWhenNewsletterWithActivationIsDisabled() {
     $newsletters_with_activation = [Newsletter::TYPE_NOTIFICATION, Newsletter::TYPE_WELCOME, Newsletter::TYPE_AUTOMATIC];
     foreach ($newsletters_with_activation as $type) {
       $newsletter = Newsletter::createOrUpdate([
@@ -896,7 +896,7 @@ class NewsletterTest extends \MailPoetTest {
     }
   }
 
-  function testUnpausesTaskWhenNewsletterWithActivationIsEnabled() {
+  public function testUnpausesTaskWhenNewsletterWithActivationIsEnabled() {
     $newsletters_with_activation = [Newsletter::TYPE_NOTIFICATION, Newsletter::TYPE_WELCOME, Newsletter::TYPE_AUTOMATIC];
     foreach ($newsletters_with_activation as $type) {
       $newsletter = Newsletter::createOrUpdate([
@@ -917,7 +917,7 @@ class NewsletterTest extends \MailPoetTest {
     }
   }
 
-  function testBlocksActivationOfEmptyNewsletter() {
+  public function testBlocksActivationOfEmptyNewsletter() {
     $newsletter = Newsletter::createOrUpdate([
       'type' => Newsletter::TYPE_NOTIFICATION,
       'body' => '[]',
@@ -928,7 +928,7 @@ class NewsletterTest extends \MailPoetTest {
     expect($newsletter->getErrors())->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOptionField::$_table);
diff --git a/tests/integration/Models/ScheduledTaskSubscriberTest.php b/tests/integration/Models/ScheduledTaskSubscriberTest.php
index 0829b5fc1b..6d6a7cc1e9 100644
--- a/tests/integration/Models/ScheduledTaskSubscriberTest.php
+++ b/tests/integration/Models/ScheduledTaskSubscriberTest.php
@@ -9,7 +9,7 @@ use MailPoet\Models\Subscriber;
 use MailPoetVendor\Idiorm\ORM;
 
 class ScheduledTaskSubscriberTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $task = ScheduledTask::create();
     $task->hydrate([
@@ -28,13 +28,13 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     $this->subscribers_counter = 0;
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->task_subscriber->task_id)->equals($this->task->id);
     expect($this->task_subscriber->subscriber_id)->equals($this->subscriber->id);
     expect($this->task_subscriber->processed)->equals(ScheduledTaskSubscriber::STATUS_UNPROCESSED);
   }
 
-  function testItCanBeUpdated() {
+  public function testItCanBeUpdated() {
     $task_subscriber = ScheduledTaskSubscriber::createOrUpdate([
       'task_id' => $this->task->id,
       'subscriber_id' => $this->subscriber->id,
@@ -43,7 +43,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     expect($task_subscriber->processed)->equals(ScheduledTaskSubscriber::STATUS_PROCESSED);
   }
 
-  function testItCanAddMultipleSubscribers() {
+  public function testItCanAddMultipleSubscribers() {
     ScheduledTaskSubscriber::deleteMany();
     $subscriber_ids = [321, 654, 987]; // sorted random ids
     ScheduledTaskSubscriber::addSubscribers($this->task->id, $subscriber_ids);
@@ -56,7 +56,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     expect($task_subscribers[2]->subscriber_id)->equals($subscriber_ids[2]);
   }
 
-  function testItCangetUnprocessedCount() {
+  public function testItCangetUnprocessedCount() {
     $count = ScheduledTaskSubscriber::getUnprocessedCount($this->task->id);
     expect($count)->equals(1);
     $this->task_subscriber->processed = ScheduledTaskSubscriber::STATUS_PROCESSED;
@@ -65,7 +65,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     expect($count)->equals(0);
   }
 
-  function testItCanGetProcessedCount() {
+  public function testItCanGetProcessedCount() {
     $count = ScheduledTaskSubscriber::getProcessedCount($this->task->id);
     expect($count)->equals(0);
     $this->task_subscriber->processed = ScheduledTaskSubscriber::STATUS_PROCESSED;
@@ -74,7 +74,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     expect($count)->equals(1);
   }
 
-  function testItCanGetTotalCount() {
+  public function testItCanGetTotalCount() {
     ScheduledTaskSubscriber::createOrUpdate([
       'task_id' => $this->task->id,
       'subscriber_id' => 555, // random new ID
@@ -84,7 +84,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     expect($count)->equals(2);
   }
 
-  function testItCanQueryListing() {
+  public function testItCanQueryListing() {
     $task_ids = $this->makeTasksWithSubscribers();
 
     $all = ScheduledTaskSubscriber::listingQuery([
@@ -124,7 +124,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
 
   }
 
-  function testItCanGetGroupsWithCounts() {
+  public function testItCanGetGroupsWithCounts() {
     $task_ids = $this->makeTasksWithSubscribers();
     $groups = ScheduledTaskSubscriber::groups([
       'params' => ['task_ids' => $task_ids],
@@ -201,7 +201,7 @@ class ScheduledTaskSubscriberTest extends \MailPoetTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
diff --git a/tests/integration/Models/ScheduledTaskTest.php b/tests/integration/Models/ScheduledTaskTest.php
index 2947273ef3..4033ac7d0c 100644
--- a/tests/integration/Models/ScheduledTaskTest.php
+++ b/tests/integration/Models/ScheduledTaskTest.php
@@ -11,7 +11,7 @@ use MailPoetVendor\Carbon\Carbon;
 use MailPoetVendor\Idiorm\ORM;
 
 class ScheduledTaskTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->task = ScheduledTask::create();
     $this->task->hydrate([
@@ -20,16 +20,16 @@ class ScheduledTaskTest extends \MailPoetTest {
     $this->task->save();
   }
 
-  function testItCanBeCompleted() {
+  public function testItCanBeCompleted() {
     $this->task->complete();
     expect($this->task->status)->equals(ScheduledTask::STATUS_COMPLETED);
   }
 
-  function testItSetsDefaultPriority() {
+  public function testItSetsDefaultPriority() {
     expect($this->task->priority)->equals(ScheduledTask::PRIORITY_MEDIUM);
   }
 
-  function testItUnPauseAllByNewsletters() {
+  public function testItUnPauseAllByNewsletters() {
     $newsletter = Newsletter::createOrUpdate([
       'type' => Newsletter::TYPE_NOTIFICATION,
     ]);
@@ -66,7 +66,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($task3_found->status)->equals(ScheduledTask::STATUS_PAUSED);
   }
 
-  function testItPauseAllByNewsletters() {
+  public function testItPauseAllByNewsletters() {
     $newsletter = Newsletter::createOrUpdate([
       'type' => Newsletter::TYPE_NOTIFICATION,
     ]);
@@ -91,7 +91,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($task2_found->status)->equals(ScheduledTask::STATUS_PAUSED);
   }
 
-  function testItDeletesRelatedScheduledTaskSubscriber() {
+  public function testItDeletesRelatedScheduledTaskSubscriber() {
     $task_id = $this->task->id;
     ScheduledTaskSubscriber::createOrUpdate([
       'task_id' => $task_id,
@@ -113,7 +113,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($count)->equals(0);
   }
 
-  function testItJsonEncodesMetaWhenSaving() {
+  public function testItJsonEncodesMetaWhenSaving() {
     $task = ScheduledTask::create();
     $meta = [
       'some' => 'value',
@@ -127,7 +127,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect(json_decode($task->meta, true))->equals($meta);
   }
 
-  function testItDoesNotJsonEncodesMetaEqualToNull() {
+  public function testItDoesNotJsonEncodesMetaEqualToNull() {
     $task = ScheduledTask::create();
     $meta = null;
     $task->meta = $meta;
@@ -139,7 +139,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($task->meta)->equals($meta);
   }
 
-  function testItCanRescheduleTasksProgressively() {
+  public function testItCanRescheduleTasksProgressively() {
     $task = $this->task;
     $task->status = null;
     $scheduled_at = $task->scheduled_at;
@@ -157,7 +157,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($timeout)->equals(ScheduledTask::MAX_RESCHEDULE_TIMEOUT);
   }
 
-  function testItCanGetDueTasks() {
+  public function testItCanGetDueTasks() {
     // due (scheduled in past)
     ScheduledTask::createOrUpdate([
       'type' => 'test',
@@ -191,7 +191,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function testItCanGetRunningTasks() {
+  public function testItCanGetRunningTasks() {
     // running (scheduled in past)
     ScheduledTask::createOrUpdate([
       'type' => 'test',
@@ -225,7 +225,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function testItCanGetCompletedTasks() {
+  public function testItCanGetCompletedTasks() {
     // completed (scheduled in past)
     ScheduledTask::createOrUpdate([
       'type' => 'test',
@@ -259,7 +259,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function testItCanGetFutureScheduledTasks() {
+  public function testItCanGetFutureScheduledTasks() {
     // scheduled (in future)
     ScheduledTask::createOrUpdate([
       'type' => 'test',
@@ -293,7 +293,7 @@ class ScheduledTaskTest extends \MailPoetTest {
     expect($tasks)->count(1);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
   }
diff --git a/tests/integration/Models/SegmentTest.php b/tests/integration/Models/SegmentTest.php
index 7f22333e6e..bb192704f3 100644
--- a/tests/integration/Models/SegmentTest.php
+++ b/tests/integration/Models/SegmentTest.php
@@ -10,7 +10,7 @@ use MailPoet\Models\SubscriberSegment;
 use MailPoetVendor\Idiorm\ORM;
 
 class SegmentTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->segment_data = [
       'name' => 'some name',
@@ -56,16 +56,16 @@ class SegmentTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->segment->id() > 0)->true();
     expect($this->segment->getErrors())->false();
   }
 
-  function testItCanHaveName() {
+  public function testItCanHaveName() {
     expect($this->segment->name)->equals($this->segment_data['name']);
   }
 
-  function nameMustBeUnique() {
+  public function nameMustBeUnique() {
     $segment = Segment::create();
     $segment->hydrate($this->segment_data);
     $result = $segment->save();
@@ -77,11 +77,11 @@ class SegmentTest extends \MailPoetTest {
     );
   }
 
-  function testItCanHaveDescription() {
+  public function testItCanHaveDescription() {
     expect($this->segment->description)->equals($this->segment_data['description']);
   }
 
-  function testItHasToBeValid() {
+  public function testItHasToBeValid() {
     $invalid_segment = Segment::create();
 
     $result = $invalid_segment->save();
@@ -91,18 +91,18 @@ class SegmentTest extends \MailPoetTest {
     expect($errors[0])->equals('Please specify a name.');
   }
 
-  function testItHasACreatedAtOnCreation() {
+  public function testItHasACreatedAtOnCreation() {
     $segment = Segment::findOne($this->segment->id);
     expect($segment->created_at)->notNull();
   }
 
-  function testItHasAnUpdatedAtOnCreation() {
+  public function testItHasAnUpdatedAtOnCreation() {
     $segment = Segment::findOne($this->segment->id);
     expect($segment->updated_at)
       ->equals($segment->created_at);
   }
 
-  function testItUpdatesTheUpdatedAtOnUpdate() {
+  public function testItUpdatesTheUpdatedAtOnUpdate() {
     $segment = Segment::findOne($this->segment->id);
     $created_at = $segment->created_at;
 
@@ -119,7 +119,7 @@ class SegmentTest extends \MailPoetTest {
     expect($is_time_updated)->true();
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     $is_created = Segment::createOrUpdate([
       'name' => 'new list',
     ]);
@@ -140,7 +140,7 @@ class SegmentTest extends \MailPoetTest {
     expect($segment->name)->equals('updated list');
   }
 
-  function testItCanHaveManySubscribers() {
+  public function testItCanHaveManySubscribers() {
     foreach ($this->subscribers_data as $subscriber_data) {
       $subscriber = Subscriber::create();
       $subscriber->hydrate($subscriber_data);
@@ -157,7 +157,7 @@ class SegmentTest extends \MailPoetTest {
     expect(count($subscribers))->equals(4);
   }
 
-  function testItCanHaveManyNewsletters() {
+  public function testItCanHaveManyNewsletters() {
     foreach ($this->newsletters_data as $newsletter_data) {
       $newsletter = Newsletter::create();
       $newsletter->hydrate($newsletter_data);
@@ -174,7 +174,7 @@ class SegmentTest extends \MailPoetTest {
     expect(count($newsletters))->equals(2);
   }
 
-  function testItCanHaveSubscriberCount() {
+  public function testItCanHaveSubscriberCount() {
     // normal subscribers
     foreach ($this->subscribers_data as $subscriber_data) {
       $subscriber = Subscriber::create();
@@ -222,7 +222,7 @@ class SegmentTest extends \MailPoetTest {
     expect($subscribers_count[Subscriber::STATUS_BOUNCED])->equals(0);
   }
 
-  function testItCanGetSegmentsWithSubscriberCount() {
+  public function testItCanGetSegmentsWithSubscriberCount() {
     foreach ($this->subscribers_data as $subscriber_data) {
       $subscriber = Subscriber::create();
       $subscriber->hydrate($subscriber_data);
@@ -236,7 +236,7 @@ class SegmentTest extends \MailPoetTest {
     expect($segments[0]['subscribers'])->equals(1);
   }
 
-  function testItCanGetSegmentsForExport() {
+  public function testItCanGetSegmentsForExport() {
     foreach ($this->subscribers_data as $index => $subscriber_data) {
       $subscriber = Subscriber::create();
       $subscriber->hydrate($subscriber_data);
@@ -256,7 +256,7 @@ class SegmentTest extends \MailPoetTest {
     expect($segments[1]['subscribers'])->equals(1);
   }
 
-  function testListingQuery() {
+  public function testListingQuery() {
     Segment::createOrUpdate([
       'name' => 'name 2',
       'description' => 'description 2',
@@ -268,13 +268,13 @@ class SegmentTest extends \MailPoetTest {
     expect($data[0]->name)->equals('some name');
   }
 
-  function testListingQueryWithGroup() {
+  public function testListingQueryWithGroup() {
     $query = Segment::listingQuery(['group' => 'trash']);
     $data = $query->findMany();
     expect($data)->count(0);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Models/SendingQueueTest.php b/tests/integration/Models/SendingQueueTest.php
index 75e310a5da..afa29374c0 100644
--- a/tests/integration/Models/SendingQueueTest.php
+++ b/tests/integration/Models/SendingQueueTest.php
@@ -10,7 +10,7 @@ use MailPoet\Util\Helpers;
 use MailPoetVendor\Idiorm\ORM;
 
 class SendingQueueTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->queue = SendingQueue::create();
     $this->queue->task_id = 0;
@@ -23,14 +23,14 @@ class SendingQueueTest extends \MailPoetTest {
     ];
   }
 
-  function testItChecksProcessedSubscribersForOldQueues() {
+  public function testItChecksProcessedSubscribersForOldQueues() {
     $subscriber_id = 123;
     expect($this->queue->isSubscriberProcessed($subscriber_id))->false();
     $this->queue->subscribers = ['processed' => [$subscriber_id]];
     expect($this->queue->isSubscriberProcessed($subscriber_id))->true();
   }
 
-  function testItChecksProcessedSubscribersForNewQueues() {
+  public function testItChecksProcessedSubscribersForNewQueues() {
     $subscriber_id = 123;
     $queue = SendingTask::create();
     $queue->setSubscribers([$subscriber_id]);
@@ -40,7 +40,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($queue->isSubscriberProcessed($subscriber_id))->true();
   }
 
-  function testItReadsSerializedRenderedNewsletterBody() {
+  public function testItReadsSerializedRenderedNewsletterBody() {
     $queue = $this->queue;
     $data = [
       'html' => 'html',
@@ -50,7 +50,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($queue->getNewsletterRenderedBody())->equals($data);
   }
 
-  function testItReadsJsonEncodedRenderedNewsletterBody() {
+  public function testItReadsJsonEncodedRenderedNewsletterBody() {
     $queue = $this->queue;
     $data = [
       'html' => 'html',
@@ -60,7 +60,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($queue->getNewsletterRenderedBody())->equals($data);
   }
 
-  function testItJsonEncodesRenderedNewsletterBodyWhenSaving() {
+  public function testItJsonEncodesRenderedNewsletterBodyWhenSaving() {
     $queue = SendingQueue::create();
     $data = [
       'html' => 'html',
@@ -77,7 +77,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect(json_decode($queue->newsletter_rendered_body, true))->equals($data);
   }
 
-  function testItJsonEncodesMetaWhenSaving() {
+  public function testItJsonEncodesMetaWhenSaving() {
     $queue = SendingQueue::create();
     $meta = [
       'some' => 'value',
@@ -93,7 +93,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect(json_decode($queue->meta, true))->equals($meta);
   }
 
-  function testItDoesNotJsonEncodesMetaEqualToNull() {
+  public function testItDoesNotJsonEncodesMetaEqualToNull() {
     $queue = SendingQueue::create();
     $meta = null;
     $queue->task_id = 0;
@@ -107,7 +107,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($queue->meta)->equals($meta);
   }
 
-  function testItReencodesSerializedObjectToJsonEncoded() {
+  public function testItReencodesSerializedObjectToJsonEncoded() {
     $queue = $this->queue;
     $newsletter_rendered_body = $this->rendered_body;
 
@@ -128,7 +128,7 @@ class SendingQueueTest extends \MailPoetTest {
     expect($sending_queue->newsletter_rendered_body)->equals(json_encode($newsletter_rendered_body));
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Models/StatisticsFormsTest.php b/tests/integration/Models/StatisticsFormsTest.php
index 26a25faf1c..34d540a3ef 100644
--- a/tests/integration/Models/StatisticsFormsTest.php
+++ b/tests/integration/Models/StatisticsFormsTest.php
@@ -6,13 +6,13 @@ use MailPoet\Models\StatisticsForms;
 
 class StatisticsFormsTest extends \MailPoetTest {
 
-  function testItCanRecordStats() {
+  public function testItCanRecordStats() {
     $record = StatisticsForms::record($form_id = 1, $subscriber_id = 2);
     expect($record->form_id)->equals(1);
     expect($record->subscriber_id)->equals(2);
   }
 
-  function testItDoesNotOverrideStats() {
+  public function testItDoesNotOverrideStats() {
     $record = StatisticsForms::record($form_id = 1, $subscriber_id = 2);
     expect($record->form_id)->equals(1);
     expect($record->subscriber_id)->equals(2);
@@ -20,7 +20,7 @@ class StatisticsFormsTest extends \MailPoetTest {
     expect(StatisticsForms::count())->equals(1);
   }
 
-  function testItCanRecordMultipleStats() {
+  public function testItCanRecordMultipleStats() {
     $record = StatisticsForms::record($form_id = 1, $subscriber_id = 2);
     $record2 = StatisticsForms::record($form_id = 2, $subscriber_id = 2);
     $record3 = StatisticsForms::record($form_id = 1, $subscriber_id = 1);
@@ -28,7 +28,7 @@ class StatisticsFormsTest extends \MailPoetTest {
     expect(StatisticsForms::count())->equals(3);
   }
 
-  function testItCannotRecordStatsWithoutFormOrSubscriber() {
+  public function testItCannotRecordStatsWithoutFormOrSubscriber() {
     $record = StatisticsForms::record($form_id = null, $subscriber_id = 1);
     expect($record)->false();
 
@@ -36,7 +36,7 @@ class StatisticsFormsTest extends \MailPoetTest {
     expect($record)->false();
   }
 
-  function testItCanReturnTheTotalSignupsOfAForm() {
+  public function testItCanReturnTheTotalSignupsOfAForm() {
     // simulate 2 signups for form #1
     StatisticsForms::record($form_id = 1, $subscriber_id = 2);
     StatisticsForms::record($form_id = 1, $subscriber_id = 1);
@@ -50,7 +50,7 @@ class StatisticsFormsTest extends \MailPoetTest {
     expect($form_2_signups)->equals(1);
   }
 
-  function _after() {
+  public function _after() {
     StatisticsForms::deleteMany();
   }
 }
diff --git a/tests/integration/Models/StatisticsUnsubscribesTest.php b/tests/integration/Models/StatisticsUnsubscribesTest.php
index 965377f206..3e4dc2deed 100644
--- a/tests/integration/Models/StatisticsUnsubscribesTest.php
+++ b/tests/integration/Models/StatisticsUnsubscribesTest.php
@@ -6,7 +6,7 @@ use MailPoet\Models\StatisticsUnsubscribes;
 use MailPoetVendor\Idiorm\ORM;
 
 class StatisticsUnsubscribesTest extends \MailPoetTest {
-  function testItCanGetExistingStatisticsRecord() {
+  public function testItCanGetExistingStatisticsRecord() {
     $unsubscribe_statistics = StatisticsUnsubscribes::create();
     $unsubscribe_statistics->newsletter_id = 123;
     $unsubscribe_statistics->subscriber_id = 456;
@@ -18,7 +18,7 @@ class StatisticsUnsubscribesTest extends \MailPoetTest {
     expect($unsubscribe_statistics->queue_id)->equals(789);
   }
 
-  function testItCanCreateNewStatisticsRecord() {
+  public function testItCanCreateNewStatisticsRecord() {
     expect(count(StatisticsUnsubscribes::findMany()))->equals(0);
     $unsubscribe_statistics = StatisticsUnsubscribes::getOrCreate(456, 123, 789);
     expect($unsubscribe_statistics->newsletter_id)->equals(123);
@@ -26,7 +26,7 @@ class StatisticsUnsubscribesTest extends \MailPoetTest {
     expect($unsubscribe_statistics->queue_id)->equals(789);
   }
 
-  function _after() {
+  public function _after() {
     ORM::for_table(StatisticsUnsubscribes::$_table)
       ->deleteMany();
   }
diff --git a/tests/integration/Models/SubscriberCustomFieldTest.php b/tests/integration/Models/SubscriberCustomFieldTest.php
index 79909f07b6..e1e2ed0314 100644
--- a/tests/integration/Models/SubscriberCustomFieldTest.php
+++ b/tests/integration/Models/SubscriberCustomFieldTest.php
@@ -6,7 +6,7 @@ use MailPoet\Models\SubscriberCustomField;
 use MailPoetVendor\Idiorm\ORM;
 
 class SubscriberCustomFieldTest extends \MailPoetTest {
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->data = [
       [
@@ -22,7 +22,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     ];
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     $subscriberCustomField = SubscriberCustomField::create();
     $subscriberCustomField->custom_field_id = $this->data[0]['custom_field_id'];
     $subscriberCustomField->subscriber_id = $this->data[0]['subscriber_id'];
@@ -32,7 +32,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     expect($subscriberCustomField->getErrors())->false();
   }
 
-  function testItCanCreateMultipleRecords() {
+  public function testItCanCreateMultipleRecords() {
     $data = array_map('array_values', $this->data);
     SubscriberCustomField::createMultiple($data);
     $records = SubscriberCustomField::findArray();
@@ -41,7 +41,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     expect($records[1]['value'])->equals('Test 2');
   }
 
-  function testItCanUpdateMultipleRecords() {
+  public function testItCanUpdateMultipleRecords() {
     $data = array_map('array_values', $this->data);
     SubscriberCustomField::createMultiple($data);
     $updated_data = $this->data;
@@ -53,7 +53,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     expect($records[1]['value'])->equals('Test 2');
   }
 
-  function testItCanDeleteManySubscriberRelations() {
+  public function testItCanDeleteManySubscriberRelations() {
     $data = array_map('array_values', $this->data);
     SubscriberCustomField::createMultiple($data);
     SubscriberCustomField::deleteManySubscriberRelations(
@@ -66,7 +66,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     expect($records)->isEmpty();
   }
 
-  function testItCanDeleteSubscriberRelations() {
+  public function testItCanDeleteSubscriberRelations() {
     $data = array_map('array_values', $this->data);
     SubscriberCustomField::createMultiple($data);
     $subscriber = (object)['id' => $this->data[0]['subscriber_id']];
@@ -75,7 +75,7 @@ class SubscriberCustomFieldTest extends \MailPoetTest {
     expect($records)->count(1);
   }
 
-  function _after() {
+  public function _after() {
     ORM::forTable(SubscriberCustomField::$_table)
       ->deleteMany();
   }
diff --git a/tests/integration/Models/SubscriberSegmentTest.php b/tests/integration/Models/SubscriberSegmentTest.php
index cb6e7d6a9a..f1a8bbffec 100644
--- a/tests/integration/Models/SubscriberSegmentTest.php
+++ b/tests/integration/Models/SubscriberSegmentTest.php
@@ -8,7 +8,7 @@ use MailPoet\Models\SubscriberSegment;
 
 class SubscriberSegmentTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->subscriber = Subscriber::createOrUpdate([
       'email' => 'john.doe@mailpoet.com',
@@ -23,7 +23,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     $this->wc_segment = Segment::getWooCommerceSegment();
   }
 
-  function testItCanSubscribeToSegments() {
+  public function testItCanSubscribeToSegments() {
     $result = SubscriberSegment::subscribeToSegments($this->subscriber, [
         $this->segment_1->id,
         $this->segment_2->id,
@@ -34,7 +34,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments)->count(2);
   }
 
-  function testItCanResetSubscriptions() {
+  public function testItCanResetSubscriptions() {
     // subscribe to the first segment
     $result = SubscriberSegment::subscribeToSegments($this->subscriber, [
         $this->segment_1->id,
@@ -55,7 +55,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments[0]['name'])->equals($this->segment_2->name);
   }
 
-  function testItCanUnsubscribeFromSegments() {
+  public function testItCanUnsubscribeFromSegments() {
     SubscriberSegment::createOrUpdate([
       'subscriber_id' => $this->subscriber->id,
       'segment_id' => $this->segment_1->id,
@@ -80,7 +80,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments[0]['name'])->equals($this->segment_2->name);
   }
 
-  function testItDoesNotUnsubscribeFromWPSegment() {
+  public function testItDoesNotUnsubscribeFromWPSegment() {
     $subscriber = $this->subscriber;
     $segment_1 = $this->segment_1;
     $segment_1->type = Segment::TYPE_WP_USERS;
@@ -131,7 +131,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscriber->subscriptions[2]['segment_id'])->equals($segment_3->id);
   }
 
-  function testItCanUnsubscribeFromAllSegments() {
+  public function testItCanUnsubscribeFromAllSegments() {
     SubscriberSegment::createOrUpdate([
       'subscriber_id' => $this->subscriber->id,
       'segment_id' => $this->segment_1->id,
@@ -159,7 +159,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscriptions_count)->equals(2);
   }
 
-  function testItCanResubscribeToAllSegments() {
+  public function testItCanResubscribeToAllSegments() {
     $result = SubscriberSegment::subscribeToSegments($this->subscriber, [
         $this->segment_1->id,
         $this->segment_2->id,
@@ -181,7 +181,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments)->count(2);
   }
 
-  function testItCanDeleteSubscriptions() {
+  public function testItCanDeleteSubscriptions() {
     SubscriberSegment::createOrUpdate([
       'subscriber_id' => $this->subscriber->id,
       'segment_id' => $this->segment_1->id,
@@ -205,7 +205,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscriptions_count)->equals(0);
   }
 
-  function testItCanDeleteManySubscriptions() {
+  public function testItCanDeleteManySubscriptions() {
     // subscribe first subscriber to segments
     SubscriberSegment::subscribeToSegments($this->subscriber, [
       $this->segment_1->id, $this->segment_2->id,
@@ -232,7 +232,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect(SubscriberSegment::count())->equals(0);
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     // create relationship between subscriber and a segment
     $result = SubscriberSegment::createOrUpdate([
       'subscriber_id' => $this->subscriber->id,
@@ -268,7 +268,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscriptions_count)->equals(1);
   }
 
-  function testItCanFilterBySubscribedStatus() {
+  public function testItCanFilterBySubscribedStatus() {
     SubscriberSegment::createOrUpdate([
       'subscriber_id' => $this->subscriber->id,
       'segment_id' => $this->segment_1->id,
@@ -287,7 +287,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscriptions_count)->equals(1);
   }
 
-  function testItCannotUnsubscribeFromWPAndWooCommerceSegments() {
+  public function testItCannotUnsubscribeFromWPAndWooCommerceSegments() {
     // subscribe to a segment, the WP segment, the WooCommerce segment
     $result = SubscriberSegment::subscribeToSegments($this->subscriber, [
         $this->segment_1->id,
@@ -306,7 +306,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments[0]['name'])->equals($this->wp_segment->name);
   }
 
-  function testItCannotDeleteSubscriptionToWPAndWooCommerceSegments() {
+  public function testItCannotDeleteSubscriptionToWPAndWooCommerceSegments() {
     // subscribe to a segment, the WP segment, the WooCommerce segment
     $result = SubscriberSegment::subscribeToSegments($this->subscriber, [
         $this->segment_1->id,
@@ -326,7 +326,7 @@ class SubscriberSegmentTest extends \MailPoetTest {
     expect($subscribed_segments[1]['name'])->equals($this->wc_segment->name);
   }
 
-  function _after() {
+  public function _after() {
     Segment::deleteMany();
     Subscriber::deleteMany();
     SubscriberSegment::deleteMany();
diff --git a/tests/integration/Models/SubscriberTest.php b/tests/integration/Models/SubscriberTest.php
index edf64aaedc..1014adde37 100644
--- a/tests/integration/Models/SubscriberTest.php
+++ b/tests/integration/Models/SubscriberTest.php
@@ -26,7 +26,7 @@ class SubscriberTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->test_data = [
       'first_name' => 'John',
@@ -43,12 +43,12 @@ class SubscriberTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanBeCreated() {
+  public function testItCanBeCreated() {
     expect($this->saved->id() > 0)->true();
     expect($this->saved->getErrors())->false();
   }
 
-  function testItHasFirstName() {
+  public function testItHasFirstName() {
     $subscriber =
       Subscriber::where('email', $this->test_data['email'])
         ->findOne();
@@ -56,7 +56,7 @@ class SubscriberTest extends \MailPoetTest {
       ->equals($this->test_data['first_name']);
   }
 
-  function testItHasLastName() {
+  public function testItHasLastName() {
     $subscriber =
       Subscriber::where('email', $this->test_data['email'])
         ->findOne();
@@ -64,7 +64,7 @@ class SubscriberTest extends \MailPoetTest {
       ->equals($this->test_data['last_name']);
   }
 
-  function testItHasEmail() {
+  public function testItHasEmail() {
     $subscriber =
       Subscriber::where('email', $this->test_data['email'])
         ->findOne();
@@ -72,7 +72,7 @@ class SubscriberTest extends \MailPoetTest {
       ->equals($this->test_data['email']);
   }
 
-  function testItShouldSetErrors() {
+  public function testItShouldSetErrors() {
     // pdo error
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
@@ -84,7 +84,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($errors[0])->contains("Unknown column 'invalid_column' in 'field list'");
   }
 
-  function testItValidatesEmailAndSetsErrors() {
+  public function testItValidatesEmailAndSetsErrors() {
     // email is required
     $subscriber = Subscriber::create();
     $subscriber->save();
@@ -105,21 +105,21 @@ class SubscriberTest extends \MailPoetTest {
     expect($errors)->contains("Your email address is invalid!");
   }
 
-  function emailMustBeUnique() {
+  public function emailMustBeUnique() {
     $conflict_subscriber = Subscriber::create();
     $conflict_subscriber->hydrate($this->test_data);
     $saved = $conflict_subscriber->save();
     expect($saved)->notEquals(true);
   }
 
-  function testItHasStatusDefaultStatusOfUnconfirmed() {
+  public function testItHasStatusDefaultStatusOfUnconfirmed() {
     $subscriber =
       Subscriber::where('email', $this->test_data['email'])
         ->findOne();
     expect($subscriber->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function testItCanChangeStatus() {
+  public function testItCanChangeStatus() {
     $subscriber = Subscriber::where('email', $this->test_data['email'])->findOne();
     $subscriber->status = Subscriber::STATUS_SUBSCRIBED;
     $subscriber->save();
@@ -131,7 +131,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber_updated->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItUpdateLastSubscribedAtCorrectly() {
+  public function testItUpdateLastSubscribedAtCorrectly() {
     $subscriber = Subscriber::where('email', $this->test_data['email'])->findOne();
     $subscriber->status = Subscriber::STATUS_UNCONFIRMED;
     $subscriber->last_subscribed_at = null;
@@ -160,7 +160,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber_updated->last_subscribed_at)->equals($last_subscribed_at->toDateTimeString());
   }
 
-  function testItHasSearchFilter() {
+  public function testItHasSearchFilter() {
     $subscriber = Subscriber::filter('search', 'john')
       ->findOne();
     expect($subscriber->first_name)->equals($this->test_data['first_name']);
@@ -172,7 +172,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->email)->equals($this->test_data['email']);
   }
 
-  function testItHasGroupFilter() {
+  public function testItHasGroupFilter() {
     $subscribers = Subscriber::filter('groupBy', Subscriber::STATUS_UNCONFIRMED)
       ->findMany();
     foreach ($subscribers as $subscriber) {
@@ -204,7 +204,7 @@ class SubscriberTest extends \MailPoetTest {
     }
   }
 
-  function testItProvidesSegmentFilter() {
+  public function testItProvidesSegmentFilter() {
     $segment = Segment::createOrUpdate([
       'name' => 'Test segment',
     ]);
@@ -227,7 +227,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($filters['segment'])->count(3);
   }
 
-  function testItAppliesSegmentFilter() {
+  public function testItAppliesSegmentFilter() {
     // remove all subscribers
     Subscriber::deleteMany();
 
@@ -286,7 +286,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscribers)->count(1);
   }
 
-  function testItCanHaveSegment() {
+  public function testItCanHaveSegment() {
     $segment = Segment::createOrUpdate([
       'name' => 'some name',
     ]);
@@ -303,7 +303,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber_segment->id)->equals($segment->id);
   }
 
-  function testItCanHaveCustomFields() {
+  public function testItCanHaveCustomFields() {
     $custom_field = CustomField::createOrUpdate([
       'name' => 'DOB',
       'type' => 'date',
@@ -320,7 +320,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->DOB)->equals($association->value);
   }
 
-  function testItCanCreateSubscriberWithCustomFields() {
+  public function testItCanCreateSubscriberWithCustomFields() {
     $custom_field = CustomField::createOrUpdate([
       'name' => 'City',
       'type' => 'text',
@@ -367,7 +367,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->{'cf_' . $custom_field_3->id})->equals('2013-07');
   }
 
-  function testItShouldUnsubscribeFromAllSegments() {
+  public function testItShouldUnsubscribeFromAllSegments() {
     $segment_1 = Segment::createOrUpdate(['name' => 'Segment 1']);
     $segment_2 = Segment::createOrUpdate(['name' => 'Segment 2']);
 
@@ -397,7 +397,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscribed_segments)->count(0);
   }
 
-  function testItCanCreateOrUpdate() {
+  public function testItCanCreateOrUpdate() {
     $data = [
       'email' => 'john.doe@mailpoet.com',
       'first_name' => 'John',
@@ -420,7 +420,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($record->last_name)->equals('Mailer');
   }
 
-  function testItCanCreateOrUpdateMultipleRecords() {
+  public function testItCanCreateOrUpdateMultipleRecords() {
     ORM::forTable(Subscriber::$_table)->deleteMany();
     $columns = [
       'first_name',
@@ -456,7 +456,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscribers[0]['status'])->equals('unsubscribed');
   }
 
-  function testItCanBeUpdatedByEmail() {
+  public function testItCanBeUpdatedByEmail() {
     $subscriber_updated = Subscriber::createOrUpdate([
       'email' => $this->test_data['email'],
       'first_name' => 'JoJo',
@@ -471,7 +471,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->last_name)->equals('DoDo');
   }
 
-  function testItCanSetCustomField() {
+  public function testItCanSetCustomField() {
     $custom_field = CustomField::createOrUpdate([
       'name' => 'Date of Birth',
       'type' => 'date',
@@ -495,7 +495,7 @@ class SubscriberTest extends \MailPoetTest {
     );
   }
 
-  function testItCanGetCustomField() {
+  public function testItCanGetCustomField() {
     $subscriber = Subscriber::findOne($this->subscriber->id());
 
     expect($subscriber->getCustomField(9999, 'default_value'))
@@ -512,7 +512,7 @@ class SubscriberTest extends \MailPoetTest {
       ->equals('non_default_value');
   }
 
-  function testItCanGetOnlySubscribedAndNonTrashedSubscribersInSegments() {
+  public function testItCanGetOnlySubscribedAndNonTrashedSubscribersInSegments() {
     $subscriber_1 = Subscriber::createOrUpdate([
       'first_name' => 'Adam',
       'last_name' => 'Smith',
@@ -561,7 +561,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscribed_subscribers_in_segment)->count(2);
   }
 
-  function testItCannotTrashWpUser() {
+  public function testItCannotTrashWpUser() {
     $wp_subscriber = Subscriber::createOrUpdate([
       'email' => 'some.wp.user@mailpoet.com',
       'first_name' => 'Some',
@@ -575,7 +575,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->deleted_at)->equals(null);
   }
 
-  function testItCannotDeleteWpUser() {
+  public function testItCannotDeleteWpUser() {
     $wp_subscriber = Subscriber::createOrUpdate([
       'email' => 'some.wp.user@mailpoet.com',
       'first_name' => 'Some',
@@ -588,7 +588,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber)->notEquals(false);
   }
 
-  function testItCannotTrashWooCommerceCustomer() {
+  public function testItCannotTrashWooCommerceCustomer() {
     $wp_subscriber = Subscriber::createOrUpdate([
       'email' => 'some.woocommerce.customer@mailpoet.com',
       'first_name' => 'Some',
@@ -602,7 +602,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber->deleted_at)->equals(null);
   }
 
-  function testItCannotDeleteWooCommerceCustomer() {
+  public function testItCannotDeleteWooCommerceCustomer() {
     $wp_subscriber = Subscriber::createOrUpdate([
       'email' => 'some.woocommerce.customer@mailpoet.com',
       'first_name' => 'Some',
@@ -615,7 +615,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($subscriber)->notEquals(false);
   }
 
-  function testItCanDeleteCustomFieldRelations() {
+  public function testItCanDeleteCustomFieldRelations() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -633,7 +633,7 @@ class SubscriberTest extends \MailPoetTest {
     expect(SubscriberCustomField::findMany())->count(1);
   }
 
-  function testItCanGetTheTotalNumberOfSubscribers() {
+  public function testItCanGetTheTotalNumberOfSubscribers() {
     // remove all subscribers
     Subscriber::deleteMany();
 
@@ -674,7 +674,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($total)->equals(1);
   }
 
-  function testItBulkTrashesSubscribers() {
+  public function testItBulkTrashesSubscribers() {
     $subscriber_with_wp_user_id_zero = Subscriber::createOrUpdate([
       'email' => 'some.wp.user0@mailpoet.com',
       'first_name' => 'Some',
@@ -693,7 +693,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($not_trashed_subscribers[0]['wp_user_id'])->equals(1);
   }
 
-  function testItBulkDeletesSubscribers() {
+  public function testItBulkDeletesSubscribers() {
     $segment = Segment::createOrUpdate(
       [
         'name' => 'test',
@@ -746,7 +746,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($not_deleted_subscribers[0]['wp_user_id'])->equals(1);
   }
 
-  function testItCanFindSubscribersInSegments() {
+  public function testItCanFindSubscribersInSegments() {
     // create 3 subscribers, segments and subscriber-segment relations
     $prepare_data = function() {
       $this->_after();
@@ -838,7 +838,7 @@ class SubscriberTest extends \MailPoetTest {
     );
   }
 
-  function testItSetsDefaultValuesForRequiredFields() {
+  public function testItSetsDefaultValuesForRequiredFields() {
     // MySQL running in strict mode requires a value to be set for certain fields
     $values = Subscriber::setRequiredFieldsDefaultValues([]);
     expect($values['first_name'])->equals('');
@@ -848,7 +848,7 @@ class SubscriberTest extends \MailPoetTest {
     expect(strlen($values['link_token']))->equals(32);
   }
 
-  function testItSetsDefaultStatusDependingOnSingupConfirmationOption() {
+  public function testItSetsDefaultStatusDependingOnSingupConfirmationOption() {
     // when signup confirmation is disabled, status should be 'subscribed'
     $this->settings->set('signup_confirmation.enabled', false);
     $values = Subscriber::setRequiredFieldsDefaultValues([]);
@@ -868,7 +868,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($values['status'])->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItSetsDefaultValuesForNewSubscribers() {
+  public function testItSetsDefaultValuesForNewSubscribers() {
     $result = Subscriber::createOrUpdate(
       [
         'email' => 'new.subscriber@example.com',
@@ -880,7 +880,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($result->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function testItDoesNotSetDefaultValuesForExistingSubscribers() {
+  public function testItDoesNotSetDefaultValuesForExistingSubscribers() {
     $existing_subscriber_data = $this->test_data;
     $result = Subscriber::createOrUpdate(
       [
@@ -892,7 +892,7 @@ class SubscriberTest extends \MailPoetTest {
     expect($result->last_name)->equals($this->test_data['last_name']);
   }
 
-  function testItExtractsCustomFieldsFromObject() {
+  public function testItExtractsCustomFieldsFromObject() {
     $data = [
       'email' => 'test@example.com',
       'cf_1' => 'Paris',
@@ -916,7 +916,7 @@ class SubscriberTest extends \MailPoetTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Models/SubscribersInDynamicSegmentTest.php b/tests/integration/Models/SubscribersInDynamicSegmentTest.php
index f84fe0ce30..17d20abceb 100644
--- a/tests/integration/Models/SubscribersInDynamicSegmentTest.php
+++ b/tests/integration/Models/SubscribersInDynamicSegmentTest.php
@@ -9,7 +9,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SubscribersInDynamicSegmentTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     $this->cleanData();
     $this->dynamic_segment = DynamicSegment::createOrUpdate([
       'name' => 'name',
@@ -40,7 +40,7 @@ class SubscribersInDynamicSegmentTest extends \MailPoetTest {
     ]);
   }
 
-  function testListingQuery() {
+  public function testListingQuery() {
     $listing_data = [
       'filter' => ['segment' => $this->dynamic_segment->id],
       'group' => 'all',
@@ -53,7 +53,7 @@ class SubscribersInDynamicSegmentTest extends \MailPoetTest {
     expect($data[1]->email)->equals('user-role-test3@example.com');
   }
 
-  function testListingQueryWithSearch() {
+  public function testListingQueryWithSearch() {
     $listing_data = [
       'filter' => ['segment' => $this->dynamic_segment->id],
       'group' => 'all',
@@ -65,7 +65,7 @@ class SubscribersInDynamicSegmentTest extends \MailPoetTest {
     expect($data[0]->email)->equals('user-role-test1@example.com');
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/Newsletter/AutomatedLatestContentTest.php b/tests/integration/Newsletter/AutomatedLatestContentTest.php
index 3328d02b6a..5cdcf6af8a 100644
--- a/tests/integration/Newsletter/AutomatedLatestContentTest.php
+++ b/tests/integration/Newsletter/AutomatedLatestContentTest.php
@@ -5,12 +5,12 @@ namespace MailPoet\Test\Newsletter;
 use MailPoet\Newsletter\AutomatedLatestContent;
 
 class AutomatedLatestContentTest extends \MailPoetTest {
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->alc = new AutomatedLatestContent();
   }
 
-  function testItCategorizesTermsToTaxonomies() {
+  public function testItCategorizesTermsToTaxonomies() {
     $args = [
       'terms' => [
         [
@@ -46,7 +46,7 @@ class AutomatedLatestContentTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanExcludeTaxonomies() {
+  public function testItCanExcludeTaxonomies() {
     $args = [
       'terms' => [
         [
diff --git a/tests/integration/Newsletter/Editor/PostContentManagerTest.php b/tests/integration/Newsletter/Editor/PostContentManagerTest.php
index 2a5db7aa70..8cc0f6c46c 100644
--- a/tests/integration/Newsletter/Editor/PostContentManagerTest.php
+++ b/tests/integration/Newsletter/Editor/PostContentManagerTest.php
@@ -8,14 +8,14 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class PostContentManagerTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->post_content = new PostContentManager(
       $this->make(WooCommerceHelper::class, ['isWooCommerceActive' => false])
     );
   }
 
-  function testFilterContentRetainsStructuralTags() {
+  public function testFilterContentRetainsStructuralTags() {
     $html = '<p>some paragraph text</p>';
     expect($this->post_content->filterContent($html, 'full'))->equals(
       '<p class="' . PostContentManager::WP_POST_CLASS . '">some paragraph text</p>'
@@ -42,7 +42,7 @@ class PostContentManagerTest extends \MailPoetTest {
     );
   }
 
-  function testFilterContentRetainsHeadings() {
+  public function testFilterContentRetainsHeadings() {
     $html = '<h1>heading 1</h1>';
     expect($this->post_content->filterContent($html, 'full'))->equals($html);
 
@@ -65,7 +65,7 @@ class PostContentManagerTest extends \MailPoetTest {
       ->equals('<p class="' . PostContentManager::WP_POST_CLASS . '">heading 3</p>');
   }
 
-  function testFilterContentRetainsTextStyling() {
+  public function testFilterContentRetainsTextStyling() {
     $text_tags = [
       '<em>emphasized></em>',
       '<b>bold</b>',
@@ -80,7 +80,7 @@ class PostContentManagerTest extends \MailPoetTest {
     }
   }
 
-  function testFilterContentRetainsImagesAndLinks() {
+  public function testFilterContentRetainsImagesAndLinks() {
     $html = '<img src="#" alt="some alt" />';
     expect($this->post_content->filterContent($html, 'full'))->equals(
       '<p class="' . PostContentManager::WP_POST_CLASS . '"><img src="#" alt="some alt" /></p>'
@@ -92,7 +92,7 @@ class PostContentManagerTest extends \MailPoetTest {
     );
   }
 
-  function testFilterContentStripsUndesirableTags() {
+  public function testFilterContentStripsUndesirableTags() {
     $undesirable_tags = [
       '<embed src="#" />',
       '<iframe src="#" />',
@@ -111,7 +111,7 @@ class PostContentManagerTest extends \MailPoetTest {
     }
   }
 
-  function testFilterContentStripsUndesirableTagsForExcerpts() {
+  public function testFilterContentStripsUndesirableTagsForExcerpts() {
     $undesirable_tags = [
       '<embed src="#" />',
       '<iframe src="#" />',
@@ -135,7 +135,7 @@ class PostContentManagerTest extends \MailPoetTest {
   }
 
 
-  function testItAppliesCustomMaxExcerptLenghViaHook() {
+  public function testItAppliesCustomMaxExcerptLenghViaHook() {
     $post_content_manager = new PostContentManager(
       $this->make(WooCommerceHelper::class, ['isWooCommerceActive' => false])
     );
@@ -157,7 +157,7 @@ class PostContentManagerTest extends \MailPoetTest {
     expect($excerpt)->equals('one two &hellip;');
   }
 
-  function testItStripsShortcodesWhenGettingPostContent() {
+  public function testItStripsShortcodesWhenGettingPostContent() {
     // shortcodes are stripped in excerpt
     $post = (object)[
       'post_excerpt' => '[shortcode]some text in excerpt[/shortcode]',
@@ -177,14 +177,14 @@ class PostContentManagerTest extends \MailPoetTest {
     expect($this->post_content->getContent($post, ''))->equals('some text in content');
   }
 
-  function testItRemovesImageCaptionsFromClassicEditorPosts() {
+  public function testItRemovesImageCaptionsFromClassicEditorPosts() {
     $post = (object)[
       'post_content' => 'Text [caption id="attachment_23" align="alignnone" width="300"]<img class="size-medium wp-image-23" src="i.png" alt="Alt" width="300" height="300" />Caption[/caption] Text [caption id="attachment_23" align="alignnone" width="300"]<img class="size-medium wp-image-23" src="i.png" alt="Alt" width="300" height="300" />Caption[/caption] Text',
     ];
     expect($this->post_content->getContent($post, 'excerpt'))->equals('Text Text Text');
   }
 
-  function testItRemovesImageCaptionsFromGutenbergPosts() {
+  public function testItRemovesImageCaptionsFromGutenbergPosts() {
     $content = <<<EOT
       <!-- wp:paragraph -->
       <p>Text</p>
diff --git a/tests/integration/Newsletter/Editor/PostContentTransformerTest.php b/tests/integration/Newsletter/Editor/PostContentTransformerTest.php
index 25e862afbd..3807815751 100644
--- a/tests/integration/Newsletter/Editor/PostContentTransformerTest.php
+++ b/tests/integration/Newsletter/Editor/PostContentTransformerTest.php
@@ -16,7 +16,7 @@ class PostContentTransformerTest extends \MailPoetTest {
   /** @var array */
   private $image_mock;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->content_mock = [
       [
@@ -32,7 +32,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     ];
   }
 
-  function testShouldAddImageAboveTitleForExcerptWithoutLayout() {
+  public function testShouldAddImageAboveTitleForExcerptWithoutLayout() {
     $args = [
       'withLayout' => false,
       'displayType' => 'excerpt',
@@ -44,7 +44,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result)->equals([$this->image_mock, $this->title_mock, $this->content_mock[0]]);
   }
 
-  function testShouldAddImageBelowTitleForExcerptWithoutLayout() {
+  public function testShouldAddImageBelowTitleForExcerptWithoutLayout() {
     $args = [
       'withLayout' => false,
       'displayType' => 'excerpt',
@@ -56,7 +56,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result)->equals([$this->title_mock, $this->image_mock, $this->content_mock[0]]);
   }
 
-  function testShouldTransformContentWithoutLayoutWhenImageIsMissing() {
+  public function testShouldTransformContentWithoutLayoutWhenImageIsMissing() {
     $args = [
       'withLayout' => false,
       'displayType' => 'excerpt',
@@ -68,7 +68,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result)->equals([$this->title_mock, $this->content_mock[0]]);
   }
 
-  function testShouldNotAddImageForTitleOnlyWhenImageIsPresentWithoutLayout() {
+  public function testShouldNotAddImageForTitleOnlyWhenImageIsPresentWithoutLayout() {
     $args = [
       'withLayout' => false,
       'displayType' => 'titleOnly',
@@ -80,7 +80,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result)->equals([$this->title_mock, $this->content_mock[0]]);
   }
 
-  function testShouldPrependTitleTextToContentTextIfFirstContentBlockIsTextual() {
+  public function testShouldPrependTitleTextToContentTextIfFirstContentBlockIsTextual() {
     $args = [
       'withLayout' => false,
       'displayType' => 'titleOnly',
@@ -96,7 +96,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result)->equals([$expected]);
   }
 
-  function testShouldCreateLayoutStructureForCenteredImageWithLayout() {
+  public function testShouldCreateLayoutStructureForCenteredImageWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -117,7 +117,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result_blocks[1]['type'])->equals('image');
   }
 
-  function testShouldCreateLayoutStructureForCenteredImageWithLayoutWithTitleAboveExcerpt() {
+  public function testShouldCreateLayoutStructureForCenteredImageWithLayoutWithTitleAboveExcerpt() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -134,7 +134,7 @@ class PostContentTransformerTest extends \MailPoetTest {
 
   }
 
-  function testShouldCreateLayoutStructureForOtherThanCenteredPositionedImageWithLayout() {
+  public function testShouldCreateLayoutStructureForOtherThanCenteredPositionedImageWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -153,7 +153,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect(count($result[1]['blocks']))->equals(2);
   }
 
-  function testShouldAddCenteredImageForExcerptWithLayout() {
+  public function testShouldAddCenteredImageForExcerptWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -165,7 +165,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[0]['blocks'][0]['blocks'])->equals([$this->title_mock, $this->image_mock, $this->content_mock[0]]);
   }
 
-  function testShouldHandleOldStructureImagePositionValueAndAddImageForExcerptWithLayout() {
+  public function testShouldHandleOldStructureImagePositionValueAndAddImageForExcerptWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -177,7 +177,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[0]['blocks'][0]['blocks'])->equals([$this->title_mock, $this->image_mock, $this->content_mock[0]]);
   }
 
-  function testShouldAddLeftPositionedImageForExcerptWithLayout() {
+  public function testShouldAddLeftPositionedImageForExcerptWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -191,7 +191,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[1]['blocks'][1]['blocks'])->equals([$this->content_mock[0]]);
   }
 
-  function testShouldAddLeftPositionedImageForExcerptWithTitleAboveExcerpt() {
+  public function testShouldAddLeftPositionedImageForExcerptWithTitleAboveExcerpt() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -206,7 +206,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[0]['blocks'][1]['blocks'][1])->equals($this->content_mock[0]);
   }
 
-  function testShouldAddRightPositionedImageForExcerptWithLayout() {
+  public function testShouldAddRightPositionedImageForExcerptWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
@@ -220,7 +220,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[1]['blocks'][1]['blocks'])->equals([$this->image_mock]);
   }
 
-  function testShouldNotAddImageForTitleOnlyWithLayout() {
+  public function testShouldNotAddImageForTitleOnlyWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'titleOnly',
@@ -232,7 +232,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     expect($result[0]['blocks'][0]['blocks'])->equals([$this->title_mock, $this->content_mock[0]]);
   }
 
-  function testShouldAddClassToParagraphsInFullPostsWithLayout() {
+  public function testShouldAddClassToParagraphsInFullPostsWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'full',
@@ -263,7 +263,7 @@ class PostContentTransformerTest extends \MailPoetTest {
     $transformer->transform($post);
   }
 
-  function testShouldNotAddClassToParagraphsInExcerptWithLayout() {
+  public function testShouldNotAddClassToParagraphsInExcerptWithLayout() {
     $args = [
       'withLayout' => true,
       'displayType' => 'excerpt',
diff --git a/tests/integration/Newsletter/Links/LinksTest.php b/tests/integration/Newsletter/Links/LinksTest.php
index 1aa55a3572..734da1f6ae 100644
--- a/tests/integration/Newsletter/Links/LinksTest.php
+++ b/tests/integration/Newsletter/Links/LinksTest.php
@@ -11,7 +11,7 @@ use MailPoet\Router\Router;
 use MailPoetVendor\Idiorm\ORM;
 
 class LinksTest extends \MailPoetTest {
-  function testItOnlyExtractsLinksFromAnchorTags() {
+  public function testItOnlyExtractsLinksFromAnchorTags() {
     $template = '<a href="http://example.com">some site</a> http://link2.com <img src="http://link3.com">';
     $result = Links::extract($template);
 
@@ -23,7 +23,7 @@ class LinksTest extends \MailPoetTest {
     );
   }
 
-  function testItOnlyHashesAndReplacesLinksInAnchorTags() {
+  public function testItOnlyHashesAndReplacesLinksInAnchorTags() {
     $template = '<a href="http://example.com"><img src="http://example.com" /></a>';
     $result = Links::process($template, 0, 0);
     expect($result[0])->equals(
@@ -35,7 +35,7 @@ class LinksTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesNotRehashExistingLinks() {
+  public function testItDoesNotRehashExistingLinks() {
     $link = NewsletterLink::create();
     $link->newsletter_id = 3;
     $link->queue_id = 3;
@@ -54,7 +54,7 @@ class LinksTest extends \MailPoetTest {
     );
   }
 
-  function testItCanExtactLinkShortcodes() {
+  public function testItCanExtactLinkShortcodes() {
     $template = '[notlink:shortcode] [link:some_link_shortcode]';
     $result = Links::extract($template);
 
@@ -66,7 +66,7 @@ class LinksTest extends \MailPoetTest {
     );
   }
 
-  function testItHashesAndReplacesLinks() {
+  public function testItHashesAndReplacesLinks() {
     $template = '<a href="http://example.com">some site</a> [link:some_link_shortcode]';
     list($updated_content, $hashed_links) = Links::process($template, 0, 0);
 
@@ -81,7 +81,7 @@ class LinksTest extends \MailPoetTest {
   }
 
 
-  function testItHashesAndReplacesLinksWithSpecialCharacters() {
+  public function testItHashesAndReplacesLinksWithSpecialCharacters() {
     $template = '<a href="http://сайт.cóm/彌撒時間">some site</a>';
     $result = Links::process($template, 0, 0);
     expect($result[0])->equals(
@@ -93,7 +93,7 @@ class LinksTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesNotReplaceUnprocessedLinks() {
+  public function testItDoesNotReplaceUnprocessedLinks() {
     $template = '<a href="http://example.com">some site</a> [link:some_link_shortcode]';
 
     $processed_links = [
@@ -116,7 +116,7 @@ class LinksTest extends \MailPoetTest {
     expect($updated_content)->notContains('http://example.com');
   }
 
-  function testItCreatesAndTransformsUrlDataObject() {
+  public function testItCreatesAndTransformsUrlDataObject() {
     $subscriber_email = 'test@example.com';
     $data = [
       'subscriber_id' => 1,
@@ -139,7 +139,7 @@ class LinksTest extends \MailPoetTest {
     expect($transformed_url_data_object)->equals($data);
   }
 
-  function testItReplacesHashedLinksWithSubscriberData() {
+  public function testItReplacesHashedLinksWithSubscriberData() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->save();
@@ -170,7 +170,7 @@ class LinksTest extends \MailPoetTest {
     }
   }
 
-  function testItCanSaveLinks() {
+  public function testItCanSaveLinks() {
     $links = [
       [
         'link' => 'http://example.com',
@@ -191,7 +191,7 @@ class LinksTest extends \MailPoetTest {
     expect($newsltter_link->url)->equals('http://example.com');
   }
 
-  function testItCanReuseAlreadySavedLinks() {
+  public function testItCanReuseAlreadySavedLinks() {
     $link = NewsletterLink::create();
     $link->newsletter_id = 1;
     $link->queue_id = 2;
@@ -213,7 +213,7 @@ class LinksTest extends \MailPoetTest {
     expect($links[0]['url'])->equals('http://example.com');
   }
 
-  function testItMatchesHashedLinks() {
+  public function testItMatchesHashedLinks() {
     $regex = Links::getLinkRegex();
     expect((boolean)preg_match($regex, '[some_tag]-123'))->false();
     expect((boolean)preg_match($regex, '[some_tag]'))->false();
@@ -221,7 +221,7 @@ class LinksTest extends \MailPoetTest {
     expect((boolean)preg_match($regex, '[mailpoet_open_data]'))->true();
   }
 
-  function testItCanConvertOnlyHashedLinkShortcodes() {
+  public function testItCanConvertOnlyHashedLinkShortcodes() {
     // create newsletter link association
     $queue_id = 1;
     $newsletter_link = NewsletterLink::create();
@@ -238,7 +238,7 @@ class LinksTest extends \MailPoetTest {
     expect($result)->contains('[mailpoet_click_data]-123');
   }
 
-  function testItCanEnsureThatUnsubscribeLinkIsAmongProcessedLinks() {
+  public function testItCanEnsureThatUnsubscribeLinkIsAmongProcessedLinks() {
     $links = [
       [
         'link' => 'http://example.com',
@@ -257,7 +257,7 @@ class LinksTest extends \MailPoetTest {
     expect(count($links))->equals(2);
   }
 
-  function testItCanConvertAllHashedLinksToUrls() {
+  public function testItCanConvertAllHashedLinksToUrls() {
     // create newsletter link associations
     $queue_id = 1;
     $newsletter_link_1 = NewsletterLink::create();
@@ -280,7 +280,7 @@ class LinksTest extends \MailPoetTest {
     expect($result)->contains($newsletter_link_2->url);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterLink::$_table);
diff --git a/tests/integration/Newsletter/RendererTest.php b/tests/integration/Newsletter/RendererTest.php
index 4777a1144c..e9d31af4c8 100644
--- a/tests/integration/Newsletter/RendererTest.php
+++ b/tests/integration/Newsletter/RendererTest.php
@@ -17,7 +17,7 @@ use MailPoet\Newsletter\Renderer\Renderer;
 class RendererTest extends \MailPoetTest {
   const COLUMN_BASE_WIDTH = 660;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->newsletter = [
       'body' => json_decode(
@@ -34,7 +34,7 @@ class RendererTest extends \MailPoetTest {
     $this->DOM_parser = new \pQuery();
   }
 
-  function testItRendersCompleteNewsletter() {
+  public function testItRendersCompleteNewsletter() {
     $this->renderer->preview = true; // do not render logo
     $template = $this->renderer->render();
     expect(isset($template['html']))->true();
@@ -53,7 +53,7 @@ class RendererTest extends \MailPoetTest {
     expect(count($DOM('.nested-vertical-container')))->equals(1);
   }
 
-  function testItRendersOneColumn() {
+  public function testItRendersOneColumn() {
     $column_content = [
       'one',
     ];
@@ -78,7 +78,7 @@ class RendererTest extends \MailPoetTest {
     expect((string)$DOM)->contains(' bgcolor="#999999"');
   }
 
-  function testItRendersTwoColumns() {
+  public function testItRendersTwoColumns() {
     $column_content = [
       'one',
       'two',
@@ -104,7 +104,7 @@ class RendererTest extends \MailPoetTest {
     expect((string)$DOM)->contains(' bgcolor="#999999"');
   }
 
-  function testItRendersThreeColumns() {
+  public function testItRendersThreeColumns() {
     $column_content = [
       'one',
       'two',
@@ -131,7 +131,7 @@ class RendererTest extends \MailPoetTest {
     expect((string)$DOM)->contains(' bgcolor="#999999"');
   }
 
-  function testItRendersScaledColumnBackgroundImage() {
+  public function testItRendersScaledColumnBackgroundImage() {
     $column_content = ['one'];
     $column_styles = ['block' => ['backgroundColor' => "#999999"]];
     $column_image = ['src' => 'https://example.com/image.jpg', 'display' => 'scale', 'width' => '1000px', 'height' => '500px'];
@@ -154,7 +154,7 @@ class RendererTest extends \MailPoetTest {
     expect($column_css)->contains('background-size: cover;');
   }
 
-  function testItRendersFitColumnBackgroundImage() {
+  public function testItRendersFitColumnBackgroundImage() {
     $column_content = ['one'];
     $column_styles = ['block' => ['backgroundColor' => "#999999"]];
     $column_image = ['src' => 'https://example.com/image.jpg', 'display' => 'fit', 'width' => '1000px', 'height' => '500px'];
@@ -177,7 +177,7 @@ class RendererTest extends \MailPoetTest {
     expect($column_css)->contains('background-size: contain;');
   }
 
-  function testItRendersTiledColumnBackgroundImage() {
+  public function testItRendersTiledColumnBackgroundImage() {
     $column_content = ['one'];
     $column_styles = ['block' => ['backgroundColor' => "#999999"]];
     $column_image = ['src' => 'https://example.com/image.jpg', 'display' => 'tile', 'width' => '1000px', 'height' => '500px'];
@@ -200,7 +200,7 @@ class RendererTest extends \MailPoetTest {
     expect($column_css)->contains('background-size: contain;');
   }
 
-  function testItRendersFallbackColumnBackgroundColorForBackgroundImage() {
+  public function testItRendersFallbackColumnBackgroundColorForBackgroundImage() {
     $column_content = ['one'];
     $column_styles = ['block' => ['backgroundColor' => 'transparent']];
     $column_image = ['src' => 'https://example.com/image.jpg', 'display' => 'tile', 'width' => '1000px', 'height' => '500px'];
@@ -219,7 +219,7 @@ class RendererTest extends \MailPoetTest {
     expect($column_css)->contains('background-color: #ffffff;');
   }
 
-  function testItRendersHeader() {
+  public function testItRendersHeader() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][0];
     $DOM = $this->DOM_parser->parseStr(Header::render($template));
@@ -230,7 +230,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('td', 0)->attr('style'))->notEmpty();
   }
 
-  function testItRendersImage() {
+  public function testItRendersImage() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][1];
     $DOM = $this->DOM_parser->parseStr(Image::render($template, self::COLUMN_BASE_WIDTH));
@@ -238,7 +238,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('tr > td > img', 0)->attr('width'))->equals(620);
   }
 
-  function testItRendersAlignedImage() {
+  public function testItRendersAlignedImage() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][1];
     // default alignment (center)
@@ -261,7 +261,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('tr > td', 0)->attr('align'))->equals('right');
   }
 
-  function testItDoesNotRenderImageWithoutSrc() {
+  public function testItDoesNotRenderImageWithoutSrc() {
     $image = [
       'src' => '',
       'width' => '100',
@@ -273,7 +273,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_image)->equals('');
   }
 
-  function testItForcesAbsoluteSrcForImages() {
+  public function testItForcesAbsoluteSrcForImages() {
     $image = [
       'src' => '/relative-path',
       'width' => '100',
@@ -298,7 +298,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_image)->contains('src="//path-without-protocol"');
   }
 
-  function testItRendersImageWithLink() {
+  public function testItRendersImageWithLink() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][1];
     $template['link'] = 'http://example.com';
@@ -308,7 +308,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('tr > td > a', 0)->attr('href'))->equals($template['link']);
   }
 
-  function testItAdjustsImageDimensions() {
+  public function testItAdjustsImageDimensions() {
     // image gets scaled down when image width > column width
     $image = [
       'width' => 800,
@@ -337,7 +337,7 @@ class RendererTest extends \MailPoetTest {
     expect($new_image_dimensions['width'])->equals(619);
   }
 
-  function testItRendersImageWithAutoDimensions() {
+  public function testItRendersImageWithAutoDimensions() {
     $image = [
       'width' => 'auto',
       'height' => 'auto',
@@ -350,7 +350,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_image)->contains('width="auto"');
   }
 
-  function testItAdjustImageDimensionsWithPx() {
+  public function testItAdjustImageDimensionsWithPx() {
     $image = [
       'width' => '1000px',
       'height' => '1000px',
@@ -363,7 +363,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_image)->contains('width="620"');
   }
 
-  function testItAdjustImageDimensionsWithoutPx() {
+  public function testItAdjustImageDimensionsWithoutPx() {
     $image = [
       'width' => '1000',
       'height' => '1000',
@@ -376,7 +376,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_image)->contains('width="620"');
   }
 
-  function testItRendersText() {
+  public function testItRendersText() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][2];
     $DOM = $this->DOM_parser->parseStr(Text::render($template));
@@ -416,7 +416,7 @@ class RendererTest extends \MailPoetTest {
       ->contains('<a');
   }
 
-  function testItRendersDivider() {
+  public function testItRendersDivider() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][3];
     $DOM = $this->DOM_parser->parseStr(Divider::render($template));
@@ -428,7 +428,7 @@ class RendererTest extends \MailPoetTest {
       ))->equals(1);
   }
 
-  function testItRendersSpacer() {
+  public function testItRendersSpacer() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][4];
     $DOM = $this->DOM_parser->parseStr(Spacer::render($template));
@@ -436,7 +436,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('tr > td.mailpoet_spacer', 0)->attr('height'))->equals(50);
   }
 
-  function testItSetsSpacerBackground() {
+  public function testItSetsSpacerBackground() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][4];
     $DOM = $this->DOM_parser->parseStr(Spacer::render($template));
@@ -447,7 +447,7 @@ class RendererTest extends \MailPoetTest {
       ->equals('#ffff');
   }
 
-  function testItCalculatesButtonWidth() {
+  public function testItCalculatesButtonWidth() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][5];
     $template['styles']['block']['width'] = '700px';
@@ -455,7 +455,7 @@ class RendererTest extends \MailPoetTest {
     expect($button_width)->equals('618px'); //(width - (2 * border width)
   }
 
-  function testItRendersButton() {
+  public function testItRendersButton() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][5];
     $DOM = $this->DOM_parser->parseStr(Button::render($template, self::COLUMN_BASE_WIDTH));
@@ -490,7 +490,7 @@ class RendererTest extends \MailPoetTest {
     )->equals(1);
   }
 
-  function testItUsesFullFontFamilyNameInElementStyles() {
+  public function testItUsesFullFontFamilyNameInElementStyles() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][5];
     $template['styles']['block']['fontFamily'] = 'Lucida';
@@ -502,7 +502,7 @@ class RendererTest extends \MailPoetTest {
     )->equals(1);
   }
 
-  function testItRendersSocialIcons() {
+  public function testItRendersSocialIcons() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][0]['blocks'][0]['blocks'][6];
     $DOM = $this->DOM_parser->parseStr(Social::render($template));
@@ -516,7 +516,7 @@ class RendererTest extends \MailPoetTest {
     expect(count($DOM('a > img')))->equals(10);
   }
 
-  function testItDoesNotRenderSocialIconsWithoutImageSrc() {
+  public function testItDoesNotRenderSocialIconsWithoutImageSrc() {
     $block = [
       'icons' => [
         'image' => '',
@@ -530,7 +530,7 @@ class RendererTest extends \MailPoetTest {
     expect($rendered_block)->equals('');
   }
 
-  function testItRendersFooter() {
+  public function testItRendersFooter() {
     $newsletter = $this->newsletter['body'];
     $template = $newsletter['content']['blocks'][3]['blocks'][0]['blocks'][0];
     $DOM = $this->DOM_parser->parseStr(Footer::render($template));
@@ -541,7 +541,7 @@ class RendererTest extends \MailPoetTest {
     expect($DOM('td', 0)->attr('style'))->notEmpty();
   }
 
-  function testItSetsSubject() {
+  public function testItSetsSubject() {
     $this->renderer->newsletter['body'] = json_decode(Fixtures::get('newsletter_body_template'), true);
     $template = $this->renderer->render();
     $DOM = $this->DOM_parser->parseStr($template['html']);
@@ -549,7 +549,7 @@ class RendererTest extends \MailPoetTest {
     expect($subject)->equals($this->newsletter['subject']);
   }
 
-  function testItSetsPreheader() {
+  public function testItSetsPreheader() {
     $this->renderer->newsletter['body'] = json_decode(Fixtures::get('newsletter_body_template'), true);
     $template = $this->renderer->render();
     $DOM = $this->DOM_parser->parseStr($template['html']);
@@ -557,7 +557,7 @@ class RendererTest extends \MailPoetTest {
     expect($preheader)->equals($this->newsletter['preheader']);
   }
 
-  function testItDoesNotAddMailpoetLogoWhenPremiumIsActive() {
+  public function testItDoesNotAddMailpoetLogoWhenPremiumIsActive() {
     $this->renderer->preview = false;
     $this->renderer->mss_activated = false;
     $this->renderer->premium_activated = true;
@@ -567,7 +567,7 @@ class RendererTest extends \MailPoetTest {
     expect($template['html'])->notContains('mailpoet_logo_newsletter.png');
   }
 
-  function testItDoesNotAddMailpoetLogoWhenMSSIsActive() {
+  public function testItDoesNotAddMailpoetLogoWhenMSSIsActive() {
     $this->renderer->preview = false;
     $this->renderer->premium_activated = false;
     $this->renderer->mss_activated = true;
@@ -577,7 +577,7 @@ class RendererTest extends \MailPoetTest {
     expect($template['html'])->notContains('mailpoet_logo_newsletter.png');
   }
 
-  function testItDoesNotAddMailpoetLogoWhenPreviewIsEnabled() {
+  public function testItDoesNotAddMailpoetLogoWhenPreviewIsEnabled() {
     $this->renderer->mss_activated = false;
     $this->renderer->premium_activated = false;
     $this->renderer->preview = true;
@@ -587,7 +587,7 @@ class RendererTest extends \MailPoetTest {
     expect($template['html'])->notContains('mailpoet_logo_newsletter.png');
   }
 
-  function testItAddsMailpoetLogo() {
+  public function testItAddsMailpoetLogo() {
     $this->renderer->newsletter['body'] = json_decode(Fixtures::get('newsletter_body_template'), true);
     $this->renderer->mss_activated = false;
     $this->renderer->premium_activated = false;
@@ -597,7 +597,7 @@ class RendererTest extends \MailPoetTest {
     expect($template['html'])->contains('mailpoet_logo_newsletter.png');
   }
 
-  function testItPostProcessesTemplate() {
+  public function testItPostProcessesTemplate() {
     $this->renderer->newsletter['body'] = json_decode(Fixtures::get('newsletter_body_template'), true);
     $template = $this->renderer->render();
     // !important should be stripped from everywhere except from with the <style> tag
diff --git a/tests/integration/Newsletter/Scheduler/AutomaticEmailTest.php b/tests/integration/Newsletter/Scheduler/AutomaticEmailTest.php
index d0fcd70b72..53fb73a02a 100644
--- a/tests/integration/Newsletter/Scheduler/AutomaticEmailTest.php
+++ b/tests/integration/Newsletter/Scheduler/AutomaticEmailTest.php
@@ -20,11 +20,11 @@ class AutomaticEmailTest extends \MailPoetTest {
   /** @var AutomaticEmailScheduler */
   private $automatic_email_scheduler;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->automatic_email_scheduler = new AutomaticEmailScheduler;
   }
-  function testItCreatesScheduledAutomaticEmailSendingTaskForUser() {
+  public function testItCreatesScheduledAutomaticEmailSendingTaskForUser() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -55,7 +55,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     expect($subscribers[0]->id)->equals($subscriber->id);
   }
 
-  function testItAddsMetaToSendingQueueWhenCreatingAutomaticEmailSendingTask() {
+  public function testItAddsMetaToSendingQueueWhenCreatingAutomaticEmailSendingTask() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -77,7 +77,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     expect($queue->getMeta())->equals($meta);
   }
 
-  function testItCreatesAutomaticEmailSendingTaskForSegment() {
+  public function testItCreatesAutomaticEmailSendingTaskForSegment() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -104,7 +104,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     expect($subscribers)->count(0);
   }
 
-  function testItDoesNotScheduleAutomaticEmailWhenGroupDoesNotMatch() {
+  public function testItDoesNotScheduleAutomaticEmailWhenGroupDoesNotMatch() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -122,7 +122,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItDoesNotScheduleAutomaticEmailWhenEventDoesNotMatch() {
+  public function testItDoesNotScheduleAutomaticEmailWhenEventDoesNotMatch() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -140,7 +140,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(0);
   }
 
-  function testItSchedulesAutomaticEmailWhenConditionMatches() {
+  public function testItSchedulesAutomaticEmailWhenConditionMatches() {
     $current_time = Carbon::createFromTimestamp(current_time('timestamp'));
     Carbon::setTestNow($current_time); // mock carbon to return current time
     $newsletter_1 = $this->_createNewsletter();
@@ -212,7 +212,7 @@ class AutomaticEmailTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
diff --git a/tests/integration/Newsletter/Scheduler/PostNotificationTest.php b/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
index a1a273023c..d138122a17 100644
--- a/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
+++ b/tests/integration/Newsletter/Scheduler/PostNotificationTest.php
@@ -22,12 +22,12 @@ class PostNotificationTest extends \MailPoetTest {
   /** @var PostNotificationScheduler */
   private $post_notification_scheduler;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->post_notification_scheduler = new PostNotificationScheduler;
   }
 
-  function testItCreatesPostNotificationSendingTask() {
+  public function testItCreatesPostNotificationSendingTask() {
     $newsletter = $this->_createNewsletter();
     $newsletter->schedule = '* 5 * * *';
 
@@ -44,7 +44,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(1);
   }
 
-  function testItCreatesPostNotificationSendingTaskIfAPausedNotificationExists() {
+  public function testItCreatesPostNotificationSendingTaskIfAPausedNotificationExists() {
     $newsletter = $this->_createNewsletter();
     $newsletter->schedule = '* 5 * * *';
 
@@ -66,7 +66,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(2);
   }
 
-  function tesIttDoesNotSchedulePostNotificationWhenNotificationWasAlreadySentForPost() {
+  public function tesIttDoesNotSchedulePostNotificationWhenNotificationWasAlreadySentForPost() {
     $newsletter = $this->_createNewsletter();
     $newsletter_post = NewsletterPost::create();
     $newsletter_post->newsletter_id = $newsletter->id;
@@ -80,7 +80,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect($queue)->false();
   }
 
-  function testItSchedulesPostNotification() {
+  public function testItSchedulesPostNotification() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -101,7 +101,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect($queue->scheduled_at)->startsWith($next_run_date->format('Y-m-d 05:00'));
   }
 
-  function testItProcessesPostNotificationScheduledForDailyDelivery() {
+  public function testItProcessesPostNotificationScheduledForDailyDelivery() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -125,7 +125,7 @@ class PostNotificationTest extends \MailPoetTest {
       ->equals('2017-01-01 14:00:00');
   }
 
-  function testItProcessesPostNotificationScheduledForWeeklyDelivery() {
+  public function testItProcessesPostNotificationScheduledForWeeklyDelivery() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -149,7 +149,7 @@ class PostNotificationTest extends \MailPoetTest {
       ->equals('2017-01-03 14:00:00');
   }
 
-  function testItProcessesPostNotificationScheduledForMonthlyDeliveryOnSpecificDay() {
+  public function testItProcessesPostNotificationScheduledForMonthlyDeliveryOnSpecificDay() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -173,7 +173,7 @@ class PostNotificationTest extends \MailPoetTest {
       ->equals('2017-01-19 14:00:00');
   }
 
-  function testItProcessesPostNotificationScheduledForMonthlyDeliveryOnLastWeekDay() {
+  public function testItProcessesPostNotificationScheduledForMonthlyDeliveryOnLastWeekDay() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -197,7 +197,7 @@ class PostNotificationTest extends \MailPoetTest {
       ->equals('2017-02-25 14:00:00');
   }
 
-  function testItProcessesPostNotificationScheduledForImmediateDelivery() {
+  public function testItProcessesPostNotificationScheduledForImmediateDelivery() {
     $newsletter_option_field = NewsletterOptionField::create();
     $newsletter_option_field->name = 'schedule';
     $newsletter_option_field->newsletter_type = Newsletter::TYPE_NOTIFICATION;
@@ -222,7 +222,7 @@ class PostNotificationTest extends \MailPoetTest {
   }
 
 
-  function testUnsearchablePostTypeDoesNotSchedulePostNotification() {
+  public function testUnsearchablePostTypeDoesNotSchedulePostNotification() {
     $hook = ContainerWrapper::getInstance()->get(Hooks::class);
 
     $newsletter = $this->_createNewsletter();
@@ -258,7 +258,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect($queue)->notequals(false);
   }
 
-  function testSchedulerWontRunIfUnsentNotificationHistoryExists() {
+  public function testSchedulerWontRunIfUnsentNotificationHistoryExists() {
     $newsletter = $this->_createNewsletter();
 
     $this->_createNewsletterOptions(
@@ -290,7 +290,7 @@ class PostNotificationTest extends \MailPoetTest {
     expect($queue)->equals(false);
   }
 
-  function _removePostNotificationHooks() {
+  public function _removePostNotificationHooks() {
     foreach (WPPosts::getTypes() as $post_type) {
       remove_filter(
         'publish_' . $post_type,
@@ -300,7 +300,7 @@ class PostNotificationTest extends \MailPoetTest {
     }
   }
 
-  function _createNewsletter() {
+  public function _createNewsletter() {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_NOTIFICATION;
     $newsletter->status = Newsletter::STATUS_ACTIVE;
@@ -309,7 +309,7 @@ class PostNotificationTest extends \MailPoetTest {
     return $newsletter;
   }
 
-  function _createNewsletterOptions($newsletter_id, $options) {
+  public function _createNewsletterOptions($newsletter_id, $options) {
     foreach ($options as $option => $value) {
       $newsletter_option_field = NewsletterOptionField::where('name', $option)->findOne();
       if (!$newsletter_option_field) {
@@ -329,7 +329,7 @@ class PostNotificationTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
diff --git a/tests/integration/Newsletter/Scheduler/SchedulerTest.php b/tests/integration/Newsletter/Scheduler/SchedulerTest.php
index 9d238358fc..a22e51211c 100644
--- a/tests/integration/Newsletter/Scheduler/SchedulerTest.php
+++ b/tests/integration/Newsletter/Scheduler/SchedulerTest.php
@@ -21,7 +21,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SchedulerTest extends \MailPoetTest {
 
-  function testItGetsActiveNewslettersFilteredByTypeAndGroup() {
+  public function testItGetsActiveNewslettersFilteredByTypeAndGroup() {
     $this->_createNewsletter($type = Newsletter::TYPE_WELCOME);
 
     // no newsletters with type "notification" should be found
@@ -44,7 +44,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(Scheduler::getNewsletters(Newsletter::TYPE_WELCOME, 'test'))->count(1);
   }
 
-  function testItCanGetNextRunDate() {
+  public function testItCanGetNextRunDate() {
     // it accepts cron syntax and returns next run date
     $current_time = Carbon::createFromTimestamp(current_time('timestamp'));
     Carbon::setTestNow($current_time); // mock carbon to return current time
@@ -54,7 +54,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(Scheduler::getNextRunDate('invalid CRON expression'))->false();
   }
 
-  function testItCanGetPreviousRunDate() {
+  public function testItCanGetPreviousRunDate() {
     // it accepts cron syntax and returns previous run date
     $current_time = Carbon::createFromTimestamp(current_time('timestamp'));
     Carbon::setTestNow($current_time); // mock carbon to return current time
@@ -64,7 +64,7 @@ class SchedulerTest extends \MailPoetTest {
     expect(Scheduler::getPreviousRunDate('invalid CRON expression'))->false();
   }
 
-  function testItFormatsDatetimeString() {
+  public function testItFormatsDatetimeString() {
     expect(Scheduler::formatDatetimeString('April 20, 2016 4pm'))
       ->equals('2016-04-20 16:00:00');
   }
@@ -101,7 +101,7 @@ class SchedulerTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
diff --git a/tests/integration/Newsletter/Scheduler/WelcomeTest.php b/tests/integration/Newsletter/Scheduler/WelcomeTest.php
index c43455663e..8e76138dda 100644
--- a/tests/integration/Newsletter/Scheduler/WelcomeTest.php
+++ b/tests/integration/Newsletter/Scheduler/WelcomeTest.php
@@ -19,12 +19,12 @@ class WelcomeTest extends \MailPoetTest {
   /** @var WelcomeScheduler */
   private $welcome_scheduler;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->welcome_scheduler = new WelcomeScheduler;
   }
 
-  function testItDoesNotCreateDuplicateWelcomeNotificationSendingTasks() {
+  public function testItDoesNotCreateDuplicateWelcomeNotificationSendingTasks() {
     $newsletter = (object)[
       'id' => 1,
       'afterTimeNumber' => 2,
@@ -45,7 +45,7 @@ class WelcomeTest extends \MailPoetTest {
     expect(SendingQueue::findMany())->count(2);
   }
 
-  function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInHours() {
+  public function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInHours() {
     $newsletter = (object)[
       'id' => 1,
       'afterTimeNumber' => 2,
@@ -64,7 +64,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->addHours(2)->format('Y-m-d H:i'));
   }
 
-  function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInDays() {
+  public function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInDays() {
     $newsletter = (object)[
       'id' => 1,
       'afterTimeNumber' => 2,
@@ -83,7 +83,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->addDays(2)->format('Y-m-d H:i'));
   }
 
-  function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInWeeks() {
+  public function testItCreatesWelcomeNotificationSendingTaskScheduledToSendInWeeks() {
     $newsletter = (object)[
       'id' => 1,
       'afterTimeNumber' => 2,
@@ -102,7 +102,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->addWeeks(2)->format('Y-m-d H:i'));
   }
 
-  function testItCreatesWelcomeNotificationSendingTaskScheduledToSendImmediately() {
+  public function testItCreatesWelcomeNotificationSendingTaskScheduledToSendImmediately() {
     $newsletter = (object)[
       'id' => 1,
       'afterTimeNumber' => 2,
@@ -120,7 +120,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->format('Y-m-d H:i'));
   }
 
-  function testItDoesNotSchedulesSubscriberWelcomeNotificationWhenSubscriberIsNotInSegment() {
+  public function testItDoesNotSchedulesSubscriberWelcomeNotificationWhenSubscriberIsNotInSegment() {
     // do not schedule when subscriber is not in segment
     $newsletter = $this->_createNewsletter();
     $this->welcome_scheduler->scheduleSubscriberWelcomeNotification(
@@ -134,7 +134,7 @@ class WelcomeTest extends \MailPoetTest {
     expect($queue)->false();
   }
 
-  function testItSchedulesSubscriberWelcomeNotification() {
+  public function testItSchedulesSubscriberWelcomeNotification() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -165,7 +165,7 @@ class WelcomeTest extends \MailPoetTest {
   }
 
 
-  function itDoesNotScheduleAnythingWhenNewsletterDoesNotExist() {
+  public function itDoesNotScheduleAnythingWhenNewsletterDoesNotExist() {
 
     // subscriber welcome notification is not scheduled
     $result = $this->welcome_scheduler->scheduleSubscriberWelcomeNotification(
@@ -182,7 +182,7 @@ class WelcomeTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItDoesNotScheduleWPUserWelcomeNotificationWhenRoleHasNotChanged() {
+  public function testItDoesNotScheduleWPUserWelcomeNotificationWhenRoleHasNotChanged() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -205,7 +205,7 @@ class WelcomeTest extends \MailPoetTest {
     expect($queue)->false();
   }
 
-  function testItDoesNotScheduleWPUserWelcomeNotificationWhenUserRoleDoesNotMatch() {
+  public function testItDoesNotScheduleWPUserWelcomeNotificationWhenUserRoleDoesNotMatch() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -227,7 +227,7 @@ class WelcomeTest extends \MailPoetTest {
     expect($queue)->false();
   }
 
-  function testItSchedulesWPUserWelcomeNotificationWhenUserRolesMatches() {
+  public function testItSchedulesWPUserWelcomeNotificationWhenUserRolesMatches() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -251,7 +251,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->addDay()->format('Y-m-d H:i'));
   }
 
-  function testItSchedulesWPUserWelcomeNotificationWhenUserHasAnyRole() {
+  public function testItSchedulesWPUserWelcomeNotificationWhenUserHasAnyRole() {
     $newsletter = $this->_createNewsletter();
     $this->_createNewsletterOptions(
       $newsletter->id,
@@ -275,7 +275,7 @@ class WelcomeTest extends \MailPoetTest {
       ->equals($current_time->addDay()->format('Y-m-d H:i'));
   }
 
-  function _createNewsletter(
+  public function _createNewsletter(
     $status = Newsletter::STATUS_ACTIVE
   ) {
     $newsletter = Newsletter::create();
@@ -286,7 +286,7 @@ class WelcomeTest extends \MailPoetTest {
     return $newsletter;
   }
 
-  function _createNewsletterOptions($newsletter_id, $options) {
+  public function _createNewsletterOptions($newsletter_id, $options) {
     foreach ($options as $option => $value) {
       $newsletter_option_field = NewsletterOptionField::where('name', $option)->findOne();
       if (!$newsletter_option_field) {
@@ -306,7 +306,7 @@ class WelcomeTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     Carbon::setTestNow();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterOption::$_table);
diff --git a/tests/integration/Newsletter/ShortcodesHelperTest.php b/tests/integration/Newsletter/ShortcodesHelperTest.php
index 4fb2e8c6a9..4021b7a3ed 100644
--- a/tests/integration/Newsletter/ShortcodesHelperTest.php
+++ b/tests/integration/Newsletter/ShortcodesHelperTest.php
@@ -7,7 +7,7 @@ use MailPoet\Newsletter\Shortcodes\ShortcodesHelper;
 use MailPoetVendor\Idiorm\ORM;
 
 class ShortcodesHelperTest extends \MailPoetTest {
-  function testGetsShortcodes() {
+  public function testGetsShortcodes() {
     $shortcodes = ShortcodesHelper::getShortcodes();
     expect(array_keys($shortcodes))->equals(
       [
@@ -20,7 +20,7 @@ class ShortcodesHelperTest extends \MailPoetTest {
     );
   }
 
-  function testItGetsCustomShortShortcodes() {
+  public function testItGetsCustomShortShortcodes() {
     $shortcodes = ShortcodesHelper::getShortcodes();
     expect(count($shortcodes['Subscriber']))->equals(5);
     $custom_field = CustomField::create();
@@ -35,7 +35,7 @@ class ShortcodesHelperTest extends \MailPoetTest {
       ->equals('[subscriber:cf_' . $custom_field->id . ']');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . CustomField::$_table);
   }
 }
diff --git a/tests/integration/Newsletter/ShortcodesTest.php b/tests/integration/Newsletter/ShortcodesTest.php
index 533fc54dea..60852c4471 100644
--- a/tests/integration/Newsletter/ShortcodesTest.php
+++ b/tests/integration/Newsletter/ShortcodesTest.php
@@ -31,7 +31,7 @@ class ShortcodesTest extends \MailPoetTest {
   /** @var SubscriptionUrlFactory */
   private $subscription_url_factory;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $referral_detector = new ReferralDetector(WPFunctions::get(), $this->settings);
@@ -50,13 +50,13 @@ class ShortcodesTest extends \MailPoetTest {
     $this->subscription_url_factory = new SubscriptionUrlFactory(WPFunctions::get(), $this->settings, new LinkTokens);
   }
 
-  function testItCanExtractShortcodes() {
+  public function testItCanExtractShortcodes() {
     $content = '[category:action] [notshortcode]';
     $shortcodes = $this->shortcodes_object->extract($content);
     expect(count($shortcodes))->equals(1);
   }
 
-  function testItCanExtractOnlySelectShortcodes() {
+  public function testItCanExtractOnlySelectShortcodes() {
     $content = '[link:action] [newsletter:action]';
     $limit = ['link'];
     $shortcodes = $this->shortcodes_object->extract($content, $limit);
@@ -64,7 +64,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect(preg_match('/link/', $shortcodes[0]))->equals(1);
   }
 
-  function testItCanMatchShortcodeDetails() {
+  public function testItCanMatchShortcodeDetails() {
     $shortcodes_object = $this->shortcodes_object;
     $content = '[category:action]';
     $details = $shortcodes_object->match($content);
@@ -84,7 +84,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($details)->isEmpty();
   }
 
-  function testItCanProcessCustomShortcodes() {
+  public function testItCanProcessCustomShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $shortcode = ['[some:shortcode]'];
     $result = $shortcodes_object->process($shortcode);
@@ -97,7 +97,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals('success');
   }
 
-  function testItCanProcessDateShortcodes() {
+  public function testItCanProcessDateShortcodes() {
     $shortcode_details = ['action' => 'd'];
     expect(Date::process($shortcode_details))->equals(date_i18n('d', current_time('timestamp')));
     $shortcode_details = ['action' => 'dordinal'];
@@ -115,7 +115,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect(Date::process($shortcode_details))->equals(date_i18n('U F', current_time('timestamp')));
   }
 
-  function testItCanProcessNewsletterShortcodes() {
+  public function testItCanProcessNewsletterShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $content =
       '<a data-post-id="' . $this->WP_post . '" href="#">latest post</a>' .
@@ -133,7 +133,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result['0'])->equals($wp_post->post_title);
   }
 
-  function itCanProcessPostNotificationNewsletterNumberShortcode() {
+  public function itCanProcessPostNotificationNewsletterNumberShortcode() {
     // create first post notification
     $post_notification_history = $this->_createNewsletter(
       $parent_id = $this->newsletter_id,
@@ -159,7 +159,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result['0'])->equals(2);
   }
 
-  function testSubscriberShortcodesRequireSubscriberObjectOrFalseValue() {
+  public function testSubscriberShortcodesRequireSubscriberObjectOrFalseValue() {
     // when subscriber is empty, default value is returned
     $shortcodes_object = new \MailPoet\Newsletter\Shortcodes\Shortcodes(
       $this->newsletter,
@@ -183,7 +183,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals('[subscriber:firstname | default:test]');
   }
 
-  function testSubscriberFirstAndLastNameShortcodesReturnDefaultValueWhenDataIsEmpty() {
+  public function testSubscriberFirstAndLastNameShortcodesReturnDefaultValueWhenDataIsEmpty() {
     // when subscriber exists but first or last names are empty, default value is returned
     $subscriber = $this->subscriber;
     $subscriber->first_name = '';
@@ -198,7 +198,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals('test');
   }
 
-  function testItCanProcessSubscriberShortcodes() {
+  public function testItCanProcessSubscriberShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $result =
       $shortcodes_object->process(['[subscriber:firstname]']);
@@ -227,7 +227,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals($subscriber_count - 1);
   }
 
-  function testItCanProcessSubscriberCustomFieldShortcodes() {
+  public function testItCanProcessSubscriberCustomFieldShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $subscriber = $this->subscriber;
     $custom_field = CustomField::create();
@@ -249,7 +249,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals($subscriber_custom_field->value);
   }
 
-  function testItCanProcessLinkShortcodes() {
+  public function testItCanProcessLinkShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $result =
       $shortcodes_object->process(['[link:subscription_unsubscribe_url]']);
@@ -263,7 +263,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result['0'])->regExp('/^http.*?endpoint=view_in_browser/');
   }
 
-  function testItReturnsShortcodeWhenTrackingEnabled() {
+  public function testItReturnsShortcodeWhenTrackingEnabled() {
     $shortcodes_object = $this->shortcodes_object;
     $shortcode = '[link:subscription_unsubscribe_url]';
     $result =
@@ -294,7 +294,7 @@ class ShortcodesTest extends \MailPoetTest {
     }
   }
 
-  function testItReturnsDefaultLinksWhenPreviewIsEnabled() {
+  public function testItReturnsDefaultLinksWhenPreviewIsEnabled() {
     $shortcodes_object = $this->shortcodes_object;
     $shortcodes_object->wp_user_preview = true;
     $shortcodes = [
@@ -314,7 +314,7 @@ class ShortcodesTest extends \MailPoetTest {
     }
   }
 
-  function testItCanProcessCustomLinkShortcodes() {
+  public function testItCanProcessCustomLinkShortcodes() {
     $shortcodes_object = $this->shortcodes_object;
     $shortcode = '[link:shortcode]';
     $result = $shortcodes_object->process([$shortcode]);
@@ -332,7 +332,7 @@ class ShortcodesTest extends \MailPoetTest {
     expect($result[0])->equals($shortcode);
   }
 
-  function _createWPPost() {
+  public function _createWPPost() {
     $data = [
       'post_title' => 'Sample Post',
       'post_content' => 'contents',
@@ -341,13 +341,13 @@ class ShortcodesTest extends \MailPoetTest {
     return wp_insert_post($data);
   }
 
-  function _createWPUser() {
+  public function _createWPUser() {
     $WP_user = wp_create_user('phoenix_test_user', 'pass', 'phoenix@test.com');
     $WP_user = get_user_by('login', 'phoenix_test_user');
     return $WP_user;
   }
 
-  function _createSubscriber() {
+  public function _createSubscriber() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(
       [
@@ -362,7 +362,7 @@ class ShortcodesTest extends \MailPoetTest {
     return Subscriber::findOne($subscriber->id);
   }
 
-  function _createNewsletter($parent_id = null, $type = Newsletter::TYPE_NOTIFICATION) {
+  public function _createNewsletter($parent_id = null, $type = Newsletter::TYPE_NOTIFICATION) {
     $newsletter = Newsletter::create();
     $newsletter->hydrate(
       [
@@ -376,7 +376,7 @@ class ShortcodesTest extends \MailPoetTest {
     return Newsletter::findOne($newsletter->id);
   }
 
-  function _createQueue() {
+  public function _createQueue() {
     $queue = SendingQueue::create();
     $queue->newsletter_id = $this->newsletter['id'];
     $queue->status = 'completed';
@@ -384,7 +384,7 @@ class ShortcodesTest extends \MailPoetTest {
     return SendingQueue::findOne($queue->id);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Newsletter/ViewInBrowserTest.php b/tests/integration/Newsletter/ViewInBrowserTest.php
index 2d69ce0421..3fb2fdcf12 100644
--- a/tests/integration/Newsletter/ViewInBrowserTest.php
+++ b/tests/integration/Newsletter/ViewInBrowserTest.php
@@ -17,7 +17,7 @@ use MailPoet\WP\Emoji;
 use MailPoetVendor\Idiorm\ORM;
 
 class ViewInBrowserTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter =
       [
@@ -108,7 +108,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     $this->newsletter_link_2 = $newsletter_link_2->save();
   }
 
-  function testItRendersNewsletter() {
+  public function testItRendersNewsletter() {
     $rendered_body = $this->view_in_browser->renderNewsletter(
       $this->newsletter,
       $this->subscriber,
@@ -118,7 +118,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->regExp('/Rendered newsletter/');
   }
 
-  function testItReusesRenderedNewsletterBodyWhenQueueExists() {
+  public function testItReusesRenderedNewsletterBodyWhenQueueExists() {
     $emoji = $this->make(
       Emoji::class,
       ['decodeEmojisInBody' => Expected::once(function ($params) {
@@ -136,7 +136,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->regExp('/Newsletter from queue/');
   }
 
-  function testItConvertsShortcodes() {
+  public function testItConvertsShortcodes() {
     $settings = SettingsController::getInstance();
     $settings->set('tracking.enabled', false);
     $rendered_body = $this->view_in_browser->renderNewsletter(
@@ -149,7 +149,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->contains(Router::NAME . '&endpoint=view_in_browser');
   }
 
-  function testItRewritesLinksToRouterEndpointWhenTrackingIsEnabled() {
+  public function testItRewritesLinksToRouterEndpointWhenTrackingIsEnabled() {
     $settings = SettingsController::getInstance();
     $settings->set('tracking.enabled', true);
     $view_in_browser = new ViewInBrowser($this->emoji, true);
@@ -164,7 +164,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->contains(Router::NAME . '&endpoint=track');
   }
 
-  function testItConvertsHashedLinksToUrlsWhenPreviewIsEnabledAndNewsletterWasSent() {
+  public function testItConvertsHashedLinksToUrlsWhenPreviewIsEnabledAndNewsletterWasSent() {
     $queue = $this->queue;
     $queue->newsletter_rendered_body = $this->queue_rendered_newsletter_with_tracking;
     $rendered_body = $this->view_in_browser->renderNewsletter(
@@ -178,7 +178,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->contains('<a href="http://google.com">');
   }
 
-  function testRemovesOpenTrackingTagWhenPreviewIsEnabledAndNewsletterWasSent() {
+  public function testRemovesOpenTrackingTagWhenPreviewIsEnabledAndNewsletterWasSent() {
     $queue = $this->queue;
     $queue->newsletter_rendered_body = $this->queue_rendered_newsletter_with_tracking;
     $rendered_body = $this->view_in_browser->renderNewsletter(
@@ -192,7 +192,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($rendered_body)->contains('<img alt="" class="" src="">');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterLink::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
diff --git a/tests/integration/Referrals/UrlDecoratorTest.php b/tests/integration/Referrals/UrlDecoratorTest.php
index 7851cc2d41..72cdcf802e 100644
--- a/tests/integration/Referrals/UrlDecoratorTest.php
+++ b/tests/integration/Referrals/UrlDecoratorTest.php
@@ -14,19 +14,19 @@ class UrlDecoratorTest extends \MailPoetTest {
   /** @var UrlDecorator */
   private $url_decorator;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->url_decorator = new UrlDecorator(WPFunctions::get(), $this->settings);
   }
 
-  function testItDoesntDoAnythingWhenNoReferralId() {
+  public function testItDoesntDoAnythingWhenNoReferralId() {
     $this->settings->set(ReferralDetector::REFERRAL_SETTING_NAME, null);
     $url = 'http://example.com';
     expect($this->url_decorator->decorate($url))->equals($url);
   }
 
-  function testItCorrectlyAddsReferralId() {
+  public function testItCorrectlyAddsReferralId() {
     $this->settings->set(ReferralDetector::REFERRAL_SETTING_NAME, 'abcdefgh');
     expect($this->url_decorator->decorate('http://example.com/'))
       ->equals('http://example.com/?ref=abcdefgh');
diff --git a/tests/integration/Router/Endpoints/SubscriptionTest.php b/tests/integration/Router/Endpoints/SubscriptionTest.php
index f010939e13..92a31e8056 100644
--- a/tests/integration/Router/Endpoints/SubscriptionTest.php
+++ b/tests/integration/Router/Endpoints/SubscriptionTest.php
@@ -10,13 +10,13 @@ use MailPoet\Subscription\Pages;
 use MailPoet\WP\Functions as WPFunctions;
 
 class SubscriptionTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     $this->data = [];
     // instantiate class
     $this->subscription = ContainerWrapper::getInstance()->get(Subscription::class);
   }
 
-  function testItDisplaysConfirmPage() {
+  public function testItDisplaysConfirmPage() {
     $pages = Stub::make(Pages::class, [
       'wp' => new WPFunctions,
       'confirm' => Expected::exactly(1),
@@ -25,7 +25,7 @@ class SubscriptionTest extends \MailPoetTest {
     $subscription->confirm($this->data);
   }
 
-  function testItDisplaysManagePage() {
+  public function testItDisplaysManagePage() {
     $pages = Stub::make(Pages::class, [
       'wp' => new WPFunctions,
       'getManageLink' => Expected::exactly(1),
@@ -37,7 +37,7 @@ class SubscriptionTest extends \MailPoetTest {
     do_shortcode('[mailpoet_manage_subscription]');
   }
 
-  function testItDisplaysUnsubscribePage() {
+  public function testItDisplaysUnsubscribePage() {
     $pages = Stub::make(Pages::class, [
       'wp' => new WPFunctions,
       'unsubscribe' => Expected::exactly(1),
diff --git a/tests/integration/Router/Endpoints/TrackTest.php b/tests/integration/Router/Endpoints/TrackTest.php
index bc240e29eb..bb63ee6bb6 100644
--- a/tests/integration/Router/Endpoints/TrackTest.php
+++ b/tests/integration/Router/Endpoints/TrackTest.php
@@ -19,7 +19,7 @@ use MailPoet\Util\Cookies;
 use MailPoetVendor\Idiorm\ORM;
 
 class TrackTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // create newsletter
     $newsletter = Newsletter::create();
@@ -58,7 +58,7 @@ class TrackTest extends \MailPoetTest {
     $this->track = new Track(new Clicks(SettingsController::getInstance(), new Cookies()), new Opens(), new LinkTokens());
   }
 
-  function testItReturnsFalseWhenTrackDataIsMissing() {
+  public function testItReturnsFalseWhenTrackDataIsMissing() {
     // queue ID is required
     $data = $this->track_data;
     unset($data['queue_id']);
@@ -73,7 +73,7 @@ class TrackTest extends \MailPoetTest {
     expect($this->track->_processTrackData($data))->false();
   }
 
-  function testItFailsWhenSubscriberTokenDoesNotMatch() {
+  public function testItFailsWhenSubscriberTokenDoesNotMatch() {
     $data = (object)array_merge(
       $this->track_data,
       [
@@ -92,7 +92,7 @@ class TrackTest extends \MailPoetTest {
     $track->_validateTrackData($data);
   }
 
-  function testItFailsWhenSubscriberIsNotOnProcessedList() {
+  public function testItFailsWhenSubscriberIsNotOnProcessedList() {
     $data = (object)array_merge(
       $this->track_data,
       [
@@ -105,7 +105,7 @@ class TrackTest extends \MailPoetTest {
     expect($this->track->_validateTrackData($data))->false();
   }
 
-  function testItDoesNotRequireWpUsersToBeOnProcessedListWhenPreviewIsEnabled() {
+  public function testItDoesNotRequireWpUsersToBeOnProcessedListWhenPreviewIsEnabled() {
     $data = (object)array_merge(
       $this->track_data,
       [
@@ -119,7 +119,7 @@ class TrackTest extends \MailPoetTest {
     expect($this->track->_validateTrackData($data))->equals($data);
   }
 
-  function testItRequiresValidQueueToGetNewsletter() {
+  public function testItRequiresValidQueueToGetNewsletter() {
     $data = $this->track_data;
     $data['newsletter_id'] = false;
     $data['queue_id'] = 99;
@@ -127,14 +127,14 @@ class TrackTest extends \MailPoetTest {
     expect($processed_data)->false();
   }
 
-  function testItGetsNewsletterFromQueue() {
+  public function testItGetsNewsletterFromQueue() {
     $data = $this->track_data;
     $data['newsletter_id'] = false;
     $processed_data = $this->track->_processTrackData($data);
     expect($processed_data->newsletter->id)->equals($this->newsletter->id);
   }
 
-  function testItProcessesTrackData() {
+  public function testItProcessesTrackData() {
     $processed_data = $this->track->_processTrackData($this->track_data);
     expect($processed_data->queue->id)->equals($this->queue->id);
     expect($processed_data->subscriber->id)->equals($this->subscriber->id);
@@ -142,7 +142,7 @@ class TrackTest extends \MailPoetTest {
     expect($processed_data->link->id)->equals($this->link->id);
   }
 
-  function testItGetsProperHashWhenDuplicateHashesExist() {
+  public function testItGetsProperHashWhenDuplicateHashesExist() {
     // create another newsletter and queue
     $newsletter = Newsletter::create();
     $newsletter->type = 'type';
@@ -171,7 +171,7 @@ class TrackTest extends \MailPoetTest {
     expect($processed_data->link->id)->equals($link->id);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterLink::$_table);
diff --git a/tests/integration/Router/Endpoints/ViewInBrowserTest.php b/tests/integration/Router/Endpoints/ViewInBrowserTest.php
index 26efc1d11a..44fb80a0c9 100644
--- a/tests/integration/Router/Endpoints/ViewInBrowserTest.php
+++ b/tests/integration/Router/Endpoints/ViewInBrowserTest.php
@@ -18,7 +18,7 @@ use MailPoet\WP\Functions;
 use MailPoetVendor\Idiorm\ORM;
 
 class ViewInBrowserTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // create newsletter
     $newsletter = Newsletter::create();
@@ -49,7 +49,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     $this->view_in_browser = new ViewInBrowser(new AccessControl(new Functions()), SettingsController::getInstance(), new LinkTokens(), new Emoji());
   }
 
-  function testItAbortsWhenBrowserPreviewDataIsMissing() {
+  public function testItAbortsWhenBrowserPreviewDataIsMissing() {
     $view_in_browser = Stub::make($this->view_in_browser, [
       '_abort' => Expected::exactly(2),
     ], $this);
@@ -63,7 +63,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     $view_in_browser->_processBrowserPreviewData($data);
   }
 
-  function testItAbortsWhenBrowserPreviewDataIsInvalid() {
+  public function testItAbortsWhenBrowserPreviewDataIsInvalid() {
     $view_in_browser = Stub::make($this->view_in_browser, [
       'link_tokens' => new LinkTokens,
       '_abort' => Expected::exactly(3),
@@ -83,7 +83,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     // subscriber has not received the newsletter
   }
 
-  function testItFailsValidationWhenSubscriberTokenDoesNotMatch() {
+  public function testItFailsValidationWhenSubscriberTokenDoesNotMatch() {
     $subscriber = $this->subscriber;
     $subscriber->email = 'random@email.com';
     $subscriber->save();
@@ -99,13 +99,13 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($this->view_in_browser->_validateBrowserPreviewData($data))->false();
   }
 
-  function testItFailsValidationWhenNewsletterIdIsProvidedButSubscriberDoesNotExist() {
+  public function testItFailsValidationWhenNewsletterIdIsProvidedButSubscriberDoesNotExist() {
     $data = (object)$this->browser_preview_data;
     $data->subscriber_id = false;
     expect($this->view_in_browser->_validateBrowserPreviewData($data))->false();
   }
 
-  function testItValidatesThatNewsletterExistsByCheckingHashFirst() {
+  public function testItValidatesThatNewsletterExistsByCheckingHashFirst() {
     $newsletter_1 = $this->newsletter;
     $newsletter_2 = Newsletter::create();
     $newsletter_2->type = 'type';
@@ -119,14 +119,14 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($result->newsletter->id)->equals($newsletter_1->id);
   }
 
-  function testItFailsValidationWhenPreviewIsEnabledButNewsletterHashNotProvided() {
+  public function testItFailsValidationWhenPreviewIsEnabledButNewsletterHashNotProvided() {
     $data = (object)$this->browser_preview_data;
     $data->newsletter_hash = false;
     $data->preview = true;
     expect($this->view_in_browser->_validateBrowserPreviewData($data))->false();
   }
 
-  function testItFailsValidationWhenSubscriberIsNotOnProcessedList() {
+  public function testItFailsValidationWhenSubscriberIsNotOnProcessedList() {
     $data = (object)$this->browser_preview_data;
     $result = $this->view_in_browser->_validateBrowserPreviewData($data);
     expect($result)->notEmpty();
@@ -138,7 +138,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($result)->false();
   }
 
-  function testItDoesNotRequireWpAdministratorToBeOnProcessedListWhenPreviewIsEnabled() {
+  public function testItDoesNotRequireWpAdministratorToBeOnProcessedListWhenPreviewIsEnabled() {
     $view_in_browser = $this->view_in_browser;
     $data = (object)array_merge(
       $this->browser_preview_data,
@@ -165,7 +165,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($view_in_browser->_validateBrowserPreviewData($data))->equals($data);
   }
 
-  function testItSetsSubscriberToLoggedInWPUserWhenPreviewIsEnabled() {
+  public function testItSetsSubscriberToLoggedInWPUserWhenPreviewIsEnabled() {
     $view_in_browser = $this->view_in_browser;
     $data = (object)array_merge(
       $this->browser_preview_data,
@@ -182,7 +182,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($result->subscriber->id)->equals(1);
   }
 
-  function testItGetsOrFindsQueueWhenItIsNotAWelcomeEmail() {
+  public function testItGetsOrFindsQueueWhenItIsNotAWelcomeEmail() {
     $data = (object)$this->browser_preview_data;
     // queue will be found when not defined
     $data->queue_id = null;
@@ -201,14 +201,14 @@ class ViewInBrowserTest extends \MailPoetTest {
     expect($result->queue)->false();
   }
 
-  function testItProcessesBrowserPreviewData() {
+  public function testItProcessesBrowserPreviewData() {
     $processed_data = $this->view_in_browser->_processBrowserPreviewData($this->browser_preview_data);
     expect($processed_data->queue->id)->equals($this->queue->id);
     expect($processed_data->subscriber->id)->equals($this->subscriber->id);
     expect($processed_data->newsletter->id)->equals($this->newsletter->id);
   }
 
-  function testItReturnsViewActionResult() {
+  public function testItReturnsViewActionResult() {
     $view_in_browser = Stub::make($this->view_in_browser, [
       'link_tokens' => new LinkTokens,
       '_displayNewsletter' => Expected::exactly(1),
@@ -218,7 +218,7 @@ class ViewInBrowserTest extends \MailPoetTest {
     $view_in_browser->view($this->browser_preview_data);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
diff --git a/tests/integration/Router/RouterTest.php b/tests/integration/Router/RouterTest.php
index 34ace142d2..4ef15435a9 100644
--- a/tests/integration/Router/RouterTest.php
+++ b/tests/integration/Router/RouterTest.php
@@ -20,7 +20,7 @@ class RouterTest extends \MailPoetTest {
   /** @var Container */
   private $container;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->router_data = [
       Router::NAME => '',
@@ -36,7 +36,7 @@ class RouterTest extends \MailPoetTest {
     $this->router = new Router($this->access_control, $this->container, $this->router_data);
   }
 
-  function testItCanGetAPIDataFromGetRequest() {
+  public function testItCanGetAPIDataFromGetRequest() {
     $data = ['data' => 'dummy data'];
     $url = 'http://example.com/?' . Router::NAME . '&endpoint=view_in_browser&action=view&data='
       . base64_encode(json_encode($data));
@@ -48,7 +48,7 @@ class RouterTest extends \MailPoetTest {
     expect($router->data)->equals($data);
   }
 
-  function testItContinuesExecutionWhenAPIRequestNotDetected() {
+  public function testItContinuesExecutionWhenAPIRequestNotDetected() {
     $router_data = $this->router_data;
     unset($router_data[Router::NAME]);
     $router = Stub::construct(
@@ -59,7 +59,7 @@ class RouterTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItTerminatesRequestWhenEndpointNotFound() {
+  public function testItTerminatesRequestWhenEndpointNotFound() {
     $router_data = $this->router_data;
     $router_data['endpoint'] = 'invalid_endpoint';
     $router = Stub::construct(
@@ -83,7 +83,7 @@ class RouterTest extends \MailPoetTest {
     );
   }
 
-  function testItTerminatesRequestWhenEndpointActionNotFound() {
+  public function testItTerminatesRequestWhenEndpointActionNotFound() {
     $router_data = $this->router_data;
     $router_data['action'] = 'invalid_action';
     $router = Stub::construct(
@@ -107,7 +107,7 @@ class RouterTest extends \MailPoetTest {
     );
   }
 
-  function testItValidatesGlobalPermission() {
+  public function testItValidatesGlobalPermission() {
     $router = $this->router;
 
     $permissions = [
@@ -138,7 +138,7 @@ class RouterTest extends \MailPoetTest {
     expect($router->validatePermissions(null, $permissions))->true();
   }
 
-  function testItValidatesEndpointActionPermission() {
+  public function testItValidatesEndpointActionPermission() {
     $router = $this->router;
 
     $permissions = [
@@ -173,7 +173,7 @@ class RouterTest extends \MailPoetTest {
     expect($router->validatePermissions('test', $permissions))->true();
   }
 
-  function testItValidatesPermissionBeforeProcessingEndpointAction() {
+  public function testItValidatesPermissionBeforeProcessingEndpointAction() {
     $router = Stub::construct(
       '\MailPoet\Router\Router',
       [$this->access_control, $this->container, $this->router_data],
@@ -195,7 +195,7 @@ class RouterTest extends \MailPoetTest {
     );
   }
 
-  function testItReturnsForbiddenResponseWhenPermissionFailsValidation() {
+  public function testItReturnsForbiddenResponseWhenPermissionFailsValidation() {
     $router = Stub::construct(
       '\MailPoet\Router\Router',
       [$this->access_control, $this->container, $this->router_data],
@@ -218,18 +218,18 @@ class RouterTest extends \MailPoetTest {
     );
   }
 
-  function testItCallsEndpointAction() {
+  public function testItCallsEndpointAction() {
     $data = ['data' => 'dummy data'];
     $result = $this->router->init();
     expect($result)->equals($data);
   }
 
-  function testItExecutesUrlParameterConflictResolverAction() {
+  public function testItExecutesUrlParameterConflictResolverAction() {
     $this->router->init();
     expect((boolean)did_action('mailpoet_conflict_resolver_router_url_query_parameters'))->true();
   }
 
-  function testItCanEncodeRequestData() {
+  public function testItCanEncodeRequestData() {
     $data = ['data' => 'dummy data'];
     $result = Router::encodeRequestData($data);
     expect($result)->equals(
@@ -237,25 +237,25 @@ class RouterTest extends \MailPoetTest {
     );
   }
 
-  function testItReturnsEmptyArrayWhenRequestDataIsAString() {
+  public function testItReturnsEmptyArrayWhenRequestDataIsAString() {
     $encoded_data = 'test';
     $result = Router::decodeRequestData($encoded_data);
     expect($result)->equals([]);
   }
 
-  function testItCanDecodeRequestData() {
+  public function testItCanDecodeRequestData() {
     $data = ['data' => 'dummy data'];
     $encoded_data = rtrim(base64_encode(json_encode($data)), '=');
     $result = Router::decodeRequestData($encoded_data);
     expect($result)->equals($data);
   }
 
-  function testItCanConvertInvalidRequestDataToArray() {
+  public function testItCanConvertInvalidRequestDataToArray() {
     $result = Router::decodeRequestData('some_invalid_data');
     expect($result)->equals([]);
   }
 
-  function testItCanBuildRequest() {
+  public function testItCanBuildRequest() {
     $data = ['data' => 'dummy data'];
     $encoded_data = rtrim(base64_encode(json_encode($data)), '=');
     $result = Router::buildRequest(
diff --git a/tests/integration/Router/RouterTestMockEndpoint.php b/tests/integration/Router/RouterTestMockEndpoint.php
index 415d376558..78d9c8aefd 100644
--- a/tests/integration/Router/RouterTestMockEndpoint.php
+++ b/tests/integration/Router/RouterTestMockEndpoint.php
@@ -14,7 +14,7 @@ class RouterTestMockEndpoint {
     'global' => AccessControl::NO_ACCESS_RESTRICTION,
   ];
 
-  function test($data) {
+  public function test($data) {
     return $data;
   }
 }
diff --git a/tests/integration/Segments/BulkActionTest.php b/tests/integration/Segments/BulkActionTest.php
index e863e11f2c..46fe1b13db 100644
--- a/tests/integration/Segments/BulkActionTest.php
+++ b/tests/integration/Segments/BulkActionTest.php
@@ -13,7 +13,7 @@ require_once('SubscribersBulkActionHandlerMock.php');
 
 class BulkActionTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cleanData();
     $this->segment_1 = Segment::createOrUpdate(['name' => 'Segment 1', 'type' => 'default']);
@@ -40,7 +40,7 @@ class BulkActionTest extends \MailPoetTest {
     SubscriberSegment::resubscribeToAllSegments($this->subscriber_2);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
@@ -50,13 +50,13 @@ class BulkActionTest extends \MailPoetTest {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
   }
 
-  function testBulkActionWithoutSegment() {
+  public function testBulkActionWithoutSegment() {
     $handler = new BulkAction([]);
     $this->setExpectedException('InvalidArgumentException');
     $handler->apply();
   }
 
-  function testBulkActionForDefaultSegment() {
+  public function testBulkActionForDefaultSegment() {
     $handler = new BulkAction([
       'listing' => ['filter' => ['segment' => $this->segment_1->id]],
       'action' => 'trash',
@@ -65,7 +65,7 @@ class BulkActionTest extends \MailPoetTest {
     expect($result['count'])->equals(1);
   }
 
-  function testBulkActionForUnknownSegment() {
+  public function testBulkActionForUnknownSegment() {
     $handler = new BulkAction([
       'listing' => ['filter' => ['segment' => 'this-segment-doesnt-exist']],
       'action' => 'trash',
@@ -74,7 +74,7 @@ class BulkActionTest extends \MailPoetTest {
     expect($result)->notEmpty();
   }
 
-  function testForUnknownSegmentTypeWithoutHandler() {
+  public function testForUnknownSegmentTypeWithoutHandler() {
     $handler = new BulkAction([
       'listing' => ['filter' => ['segment' => $this->segment_2->id]],
       'action' => 'trash',
@@ -84,7 +84,7 @@ class BulkActionTest extends \MailPoetTest {
     $handler->apply();
   }
 
-  function testBulkActionUsingFilter() {
+  public function testBulkActionUsingFilter() {
     $mock = Stub::makeEmpty('\MailPoet\Test\Segments\SubscribersBulkActionHandlerMock', ['apply']);
     $mock
       ->expects($this->once())
diff --git a/tests/integration/Segments/DynamicListingsHandlerMock.php b/tests/integration/Segments/DynamicListingsHandlerMock.php
index adc7d8a9ba..fdb1317988 100644
--- a/tests/integration/Segments/DynamicListingsHandlerMock.php
+++ b/tests/integration/Segments/DynamicListingsHandlerMock.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Segments;
 
 class DynamicListingsHandlerMock {
 
-  function get() {
+  public function get() {
 
   }
 
diff --git a/tests/integration/Segments/FinderMock.php b/tests/integration/Segments/FinderMock.php
index 8f4c60705b..af318f7eaa 100644
--- a/tests/integration/Segments/FinderMock.php
+++ b/tests/integration/Segments/FinderMock.php
@@ -4,12 +4,12 @@ namespace MailPoet\Segments;
 
 class FinderMock {
 
-  function getSubscriberIdsInSegment() {
+  public function getSubscriberIdsInSegment() {
 
   }
 
-  function findSubscribersInSegment() {
-    
+  public function findSubscribersInSegment() {
+
   }
 
 }
\ No newline at end of file
diff --git a/tests/integration/Segments/SubscribersBulkActionHandlerMock.php b/tests/integration/Segments/SubscribersBulkActionHandlerMock.php
index 7a659c10eb..b2d3c9d627 100644
--- a/tests/integration/Segments/SubscribersBulkActionHandlerMock.php
+++ b/tests/integration/Segments/SubscribersBulkActionHandlerMock.php
@@ -4,7 +4,7 @@ namespace MailPoet\Test\Segments;
 
 class SubscribersBulkActionHandlerMock {
 
-  function apply() {
+  public function apply() {
 
   }
 
diff --git a/tests/integration/Segments/SubscribersFinderTest.php b/tests/integration/Segments/SubscribersFinderTest.php
index 95fdafe7bf..1f828805b7 100644
--- a/tests/integration/Segments/SubscribersFinderTest.php
+++ b/tests/integration/Segments/SubscribersFinderTest.php
@@ -16,7 +16,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class SubscribersFinderTest extends \MailPoetTest {
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
@@ -55,7 +55,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     $this->sending = SendingTask::create();
   }
 
-  function testFindSubscribersInSegmentInSegmentDefaultSegment() {
+  public function testFindSubscribersInSegmentInSegmentDefaultSegment() {
     $finder = new SubscribersFinder();
     $deleted_segment_id = 1000; // non-existent segment
     $subscribers = $finder->findSubscribersInSegments([$this->subscriber_2->id], [$this->segment_1->id, $deleted_segment_id]);
@@ -63,7 +63,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($subscribers[$this->subscriber_2->id])->equals($this->subscriber_2->id);
   }
 
-  function testFindSubscribersInSegmentUsingFinder() {
+  public function testFindSubscribersInSegmentUsingFinder() {
     $mock = Stub::makeEmpty('MailPoet\Segments\FinderMock', ['findSubscribersInSegment']);
     $mock
       ->expects($this->once())
@@ -81,7 +81,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($subscribers)->contains($this->subscriber_3->id);
   }
 
-  function testFindSubscribersInSegmentUsingFinderMakesResultUnique() {
+  public function testFindSubscribersInSegmentUsingFinderMakesResultUnique() {
     $mock = Stub::makeEmpty('MailPoet\Segments\FinderMock', ['findSubscribersInSegment']);
     $mock
       ->expects($this->exactly(2))
@@ -98,7 +98,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($subscribers)->count(1);
   }
 
-  function testItAddsSubscribersToTaskFromStaticSegments() {
+  public function testItAddsSubscribersToTaskFromStaticSegments() {
     $finder = new SubscribersFinder();
     $subscribers_count = $finder->addSubscribersToTaskFromSegments(
       $this->sending->task(),
@@ -111,7 +111,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($this->sending->getSubscribers())->equals([$this->subscriber_2->id]);
   }
 
-  function testItDoesNotAddSubscribersToTaskFromNoSegment() {
+  public function testItDoesNotAddSubscribersToTaskFromNoSegment() {
     $finder = new SubscribersFinder();
     $subscribers_count = $finder->addSubscribersToTaskFromSegments(
       $this->sending->task(),
@@ -122,7 +122,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($subscribers_count)->equals(0);
   }
 
-  function testItAddsSubscribersToTaskFromDynamicSegments() {
+  public function testItAddsSubscribersToTaskFromDynamicSegments() {
     $mock = Stub::makeEmpty('MailPoet\Segments\FinderMock', ['getSubscriberIdsInSegment']);
     $mock
       ->expects($this->once())
@@ -145,7 +145,7 @@ class SubscribersFinderTest extends \MailPoetTest {
     expect($this->sending->getSubscribers())->equals([$this->subscriber_1->id]);
   }
 
-  function testItAddsSubscribersToTaskFromStaticAndDynamicSegments() {
+  public function testItAddsSubscribersToTaskFromStaticAndDynamicSegments() {
     $finder = new SubscribersFinder();
 
     $mock = Stub::makeEmpty('MailPoet\Segments\FinderMock', ['getSubscriberIdsInSegment']);
diff --git a/tests/integration/Segments/SubscribersListingsTest.php b/tests/integration/Segments/SubscribersListingsTest.php
index 1c4f2a73e0..6ea986a4a0 100644
--- a/tests/integration/Segments/SubscribersListingsTest.php
+++ b/tests/integration/Segments/SubscribersListingsTest.php
@@ -17,7 +17,7 @@ class SubscribersListingsTest extends \MailPoetTest {
   /** @var SubscribersListings */
   private $finder;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->finder = ContainerWrapper::getInstance()->get(SubscribersListings::class);
     $this->cleanData();
@@ -45,7 +45,7 @@ class SubscribersListingsTest extends \MailPoetTest {
     SubscriberSegment::resubscribeToAllSegments($this->subscriber_2);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
@@ -55,22 +55,22 @@ class SubscribersListingsTest extends \MailPoetTest {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
   }
 
-  function testTryToGetListingsWithoutPassingSegment() {
+  public function testTryToGetListingsWithoutPassingSegment() {
     $this->setExpectedException('InvalidArgumentException');
     $this->finder->getListingsInSegment([]);
   }
 
-  function testGetListingsForDefaultSegment() {
+  public function testGetListingsForDefaultSegment() {
     $listings = $this->finder->getListingsInSegment(['filter' => ['segment' => $this->segment_1->id]]);
     expect($listings['items'])->count(1);
   }
 
-  function testGetListingsForNonExistingSegmen() {
+  public function testGetListingsForNonExistingSegmen() {
     $listings = $this->finder->getListingsInSegment(['filter' => ['segment' => 'non-existing-id']]);
     expect($listings['items'])->notEmpty();
   }
 
-  function testGetListingsUsingFilter() {
+  public function testGetListingsUsingFilter() {
     $mock = Stub::makeEmpty('MailPoet\Test\Segments\DynamicListingsHandlerMock', ['get']);
     $mock
       ->expects($this->once())
@@ -86,7 +86,7 @@ class SubscribersListingsTest extends \MailPoetTest {
     expect($listings)->equals('dynamic listings');
   }
 
-  function testTryToGetListingsForSegmentWithoutHandler() {
+  public function testTryToGetListingsForSegmentWithoutHandler() {
     $this->setExpectedException('InvalidArgumentException');
     remove_all_filters('mailpoet_get_subscribers_listings_in_segment_handlers');
     $this->finder->getListingsInSegment(['filter' => ['segment' => $this->segment_2->id]]);
diff --git a/tests/integration/Segments/WPTest.php b/tests/integration/Segments/WPTest.php
index 440a01ef9e..88c3599cfa 100644
--- a/tests/integration/Segments/WPTest.php
+++ b/tests/integration/Segments/WPTest.php
@@ -20,7 +20,7 @@ class WPTest extends \MailPoetTest  {
   /** @var SettingsController */
   private $settings;
 
-  function testSynchronizeUserKeepsStatusOfOldUser() {
+  public function testSynchronizeUserKeepsStatusOfOldUser() {
     $random_number = rand();
     $id = $this->insertUser($random_number);
     $subscriber = Subscriber::createOrUpdate([
@@ -33,7 +33,7 @@ class WPTest extends \MailPoetTest  {
     expect($db_subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testSynchronizeUserStatusIsSubscribedForNewUserWithSignUpConfirmationDisabled() {
+  public function testSynchronizeUserStatusIsSubscribedForNewUserWithSignUpConfirmationDisabled() {
     $this->settings->set('signup_confirmation', ['enabled' => '0']);
     $random_number = rand();
     $id = $this->insertUser($random_number);
@@ -42,7 +42,7 @@ class WPTest extends \MailPoetTest  {
     expect($wp_subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testSynchronizeUserStatusIsUnconfirmedForNewUserWithSignUpConfirmationEnabled() {
+  public function testSynchronizeUserStatusIsUnconfirmedForNewUserWithSignUpConfirmationEnabled() {
     $this->settings->set('signup_confirmation', ['enabled' => '1']);
     $random_number = rand();
     $id = $this->insertUser($random_number);
@@ -51,7 +51,7 @@ class WPTest extends \MailPoetTest  {
     expect($wp_subscriber->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function testSynchronizeUsersStatusIsSubscribedForNewUsersWithSignUpConfirmationDisabled() {
+  public function testSynchronizeUsersStatusIsSubscribedForNewUsersWithSignUpConfirmationDisabled() {
     $this->settings->set('signup_confirmation', ['enabled' => '0']);
     $this->insertUser();
     $this->insertUser();
@@ -62,7 +62,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribers[1]->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testSynchronizeUsersStatusIsUnconfirmedForNewUsersWithSignUpConfirmationEnabled() {
+  public function testSynchronizeUsersStatusIsUnconfirmedForNewUsersWithSignUpConfirmationEnabled() {
     $this->settings->set('signup_confirmation', ['enabled' => '1']);
     $this->insertUser();
     $this->insertUser();
@@ -73,7 +73,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribers[1]->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function testItSynchronizeNewUsers() {
+  public function testItSynchronizeNewUsers() {
     $this->insertUser();
     $this->insertUser();
     WP::synchronizeUsers();
@@ -83,7 +83,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribersCount)->equals(3);
   }
 
-  function testItSynchronizesPresubscribedUsers() {
+  public function testItSynchronizesPresubscribedUsers() {
     $random_number = 12345;
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user-sync-test' . $random_number . '@example.com',
@@ -97,7 +97,7 @@ class WPTest extends \MailPoetTest  {
     expect($wp_subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItSynchronizeEmails() {
+  public function testItSynchronizeEmails() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     $this->updateWPUserEmail($id, 'user-sync-test-xx@email.com');
@@ -106,7 +106,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->email)->equals('user-sync-test-xx@email.com');
   }
 
-  function testRemovesUsersWithEmptyEmailsFromSunscribersDuringSynchronization() {
+  public function testRemovesUsersWithEmptyEmailsFromSunscribersDuringSynchronization() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     $this->updateWPUserEmail($id, '');
@@ -115,7 +115,7 @@ class WPTest extends \MailPoetTest  {
     $this->deleteWPUser($id);
   }
 
-  function testRemovesUsersWithInvalidEmailsFromSunscribersDuringSynchronization() {
+  public function testRemovesUsersWithInvalidEmailsFromSunscribersDuringSynchronization() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     $this->updateWPUserEmail($id, 'ivalid.@email.com');
@@ -124,7 +124,7 @@ class WPTest extends \MailPoetTest  {
     $this->deleteWPUser($id);
   }
 
-  function testItDoesNotSynchronizeEmptyEmailsForNewUsers() {
+  public function testItDoesNotSynchronizeEmptyEmailsForNewUsers() {
     $id = $this->insertUser();
     $this->updateWPUserEmail($id, '');
     WP::synchronizeUsers();
@@ -133,7 +133,7 @@ class WPTest extends \MailPoetTest  {
     $this->deleteWPUser($id);
   }
 
-  function testItSynchronizeFirstNames() {
+  public function testItSynchronizeFirstNames() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     update_user_meta($id, 'first_name', 'First name');
@@ -142,7 +142,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->first_name)->equals('First name');
   }
 
-  function testItSynchronizeLastNames() {
+  public function testItSynchronizeLastNames() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     update_user_meta($id, 'last_name', 'Last name');
@@ -151,7 +151,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->last_name)->equals('Last name');
   }
 
-  function testItSynchronizeFirstNamesUsingDisplayName() {
+  public function testItSynchronizeFirstNamesUsingDisplayName() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     $this->updateWPUserDisplayName($id, 'First name');
@@ -160,7 +160,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->first_name)->equals('First name');
   }
 
-  function testItSynchronizeFirstNamesFromMetaNotDisplayName() {
+  public function testItSynchronizeFirstNamesFromMetaNotDisplayName() {
     $id = $this->insertUser();
     update_user_meta($id, 'first_name', 'First name');
     $this->updateWPUserDisplayName($id, 'display_name');
@@ -169,7 +169,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->first_name)->equals('First name');
   }
 
-  function testItSynchronizeSegment() {
+  public function testItSynchronizeSegment() {
     $this->insertUser();
     $this->insertUser();
     $this->insertUser();
@@ -178,7 +178,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribers->count())->equals(3);
   }
 
-  function testItRemovesUsersFromTrash() {
+  public function testItRemovesUsersFromTrash() {
     $id = $this->insertUser();
     WP::synchronizeUsers();
     $subscriber = Subscriber::where("wp_user_id", $id)->findOne();
@@ -189,7 +189,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscriber->deleted_at)->null();
   }
 
-  function testItSynchronizesDeletedWPUsersUsingHooks() {
+  public function testItSynchronizesDeletedWPUsersUsingHooks() {
     $id = $this->insertUser();
     $this->insertUser();
     WP::synchronizeUsers();
@@ -200,7 +200,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribersCount)->equals(1);
   }
 
-  function testItRemovesOrphanedSubscribers() {
+  public function testItRemovesOrphanedSubscribers() {
     $this->insertUser();
     $id = $this->insertUser();
     WP::synchronizeUsers();
@@ -210,7 +210,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribers->count())->equals(1);
   }
 
-  function testItDoesntDeleteNonWPData() {
+  public function testItDoesntDeleteNonWPData() {
     $this->insertUser();
     // wp_user_id is null
     $subscriber = Subscriber::create();
@@ -249,7 +249,7 @@ class WPTest extends \MailPoetTest  {
     $subscriber3->delete();
   }
 
-  function testItRemovesSubscribersInWPSegmentWithoutWPId() {
+  public function testItRemovesSubscribersInWPSegmentWithoutWPId() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'first_name' => 'Mike',
@@ -271,7 +271,7 @@ class WPTest extends \MailPoetTest  {
     expect($subscribersCount)->equals(0);
   }
 
-  function testItRemovesSubscribersInWPSegmentWithoutEmail() {
+  public function testItRemovesSubscribersInWPSegmentWithoutEmail() {
     $id = $this->insertUser();
     $this->updateWPUserEmail($id, '');
     $subscriber = Subscriber::create();
@@ -296,7 +296,7 @@ class WPTest extends \MailPoetTest  {
     expect($db_subscriber)->isEmpty();
   }
 
-  function testItMarksSpammySubscribersAsUnconfirmed() {
+  public function testItMarksSpammySubscribersAsUnconfirmed() {
     $random_number = rand();
     $id = $this->insertUser($random_number);
     $subscriber = Subscriber::createOrUpdate([
@@ -310,7 +310,7 @@ class WPTest extends \MailPoetTest  {
     expect($db_subscriber->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function testItMarksSpammySubscribersWithUserStatus2AsUnconfirmed() {
+  public function testItMarksSpammySubscribersWithUserStatus2AsUnconfirmed() {
     global $wpdb;
     $column_exists = $wpdb->query(sprintf('SHOW COLUMNS FROM `%s` LIKE "user_status"', $wpdb->users));
     if (!$column_exists) {
@@ -333,13 +333,13 @@ class WPTest extends \MailPoetTest  {
     expect($db_subscriber->status)->equals(Subscriber::STATUS_UNCONFIRMED);
   }
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = ContainerWrapper::getInstance()->get(SettingsController::class);
     $this->cleanData();
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
   }
 
diff --git a/tests/integration/Segments/WooCommerceTest.php b/tests/integration/Segments/WooCommerceTest.php
index 7f0da6261d..555a33ec07 100644
--- a/tests/integration/Segments/WooCommerceTest.php
+++ b/tests/integration/Segments/WooCommerceTest.php
@@ -25,14 +25,14 @@ class WooCommerceTest extends \MailPoetTest  {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     $this->woocommerce_segment = ContainerWrapper::getInstance()->get(WooCommerceSegment::class);
     $this->settings = ContainerWrapper::getInstance()->get(SettingsController::class);
     $this->cleanData();
     $this->addCustomerRole();
   }
 
-  function testItSynchronizesNewRegisteredCustomer() {
+  public function testItSynchronizesNewRegisteredCustomer() {
     $user = $this->insertRegisteredCustomer();
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
@@ -57,7 +57,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->deleted_at)->equals(null);
   }
 
-  function testItSynchronizesUpdatedRegisteredCustomer() {
+  public function testItSynchronizesUpdatedRegisteredCustomer() {
     $user = $this->insertRegisteredCustomer();
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
@@ -81,7 +81,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->status)->equals(Subscriber::STATUS_UNSUBSCRIBED); // no overriding
   }
 
-  function testItSynchronizesDeletedRegisteredCustomer() {
+  public function testItSynchronizesDeletedRegisteredCustomer() {
     $wc_segment = Segment::getWooCommerceSegment();
     $user = $this->insertRegisteredCustomer();
     $subscriber = Subscriber::create();
@@ -104,7 +104,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect(SubscriberSegment::findOne($association->id))->isEmpty();
   }
 
-  function testItSynchronizesNewGuestCustomer() {
+  public function testItSynchronizesNewGuestCustomer() {
     $guest = $this->insertGuestCustomer();
     $hook = 'woocommerce_checkout_update_order_meta';
     $this->woocommerce_segment->synchronizeGuestCustomer($guest['order_id'], $hook);
@@ -116,7 +116,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->source)->equals(Source::WOOCOMMERCE_USER);
   }
 
-  function testItSynchronizesCustomers() {
+  public function testItSynchronizesCustomers() {
     $this->settings->set('mailpoet_subscribe_old_woocommerce_customers', ['dummy' => '1', 'enabled' => '1']);
     $user = $this->insertRegisteredCustomer();
     $guest = $this->insertGuestCustomer();
@@ -131,7 +131,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->source)->equals(Source::WOOCOMMERCE_USER);
   }
 
-  function testItSynchronizesNewCustomers() {
+  public function testItSynchronizesNewCustomers() {
     $this->insertRegisteredCustomer();
     $this->insertGuestCustomer();
     $this->woocommerce_segment->synchronizeCustomers();
@@ -142,7 +142,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscribersCount)->equals(4);
   }
 
-  function testItSynchronizesPresubscribedRegisteredCustomers() {
+  public function testItSynchronizesPresubscribedRegisteredCustomers() {
     $random_number = 12345;
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user-sync-test' . $random_number . '@example.com',
@@ -159,7 +159,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($wp_subscriber->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItSynchronizesPresubscribedGuestCustomers() {
+  public function testItSynchronizesPresubscribedGuestCustomers() {
     $random_number = 12345;
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user-sync-test' . $random_number . '@example.com',
@@ -176,7 +176,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($wp_subscriber->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItDoesNotSynchronizeEmptyEmailsForNewUsers() {
+  public function testItDoesNotSynchronizeEmptyEmailsForNewUsers() {
     $guest = $this->insertGuestCustomer();
     update_post_meta($guest['order_id'], '_billing_email', '');
     $this->woocommerce_segment->synchronizeCustomers();
@@ -185,7 +185,7 @@ class WooCommerceTest extends \MailPoetTest  {
     $this->deleteOrder($guest['order_id']);
   }
 
-  function testItDoesNotSynchronizeInvalidEmailsForNewUsers() {
+  public function testItDoesNotSynchronizeInvalidEmailsForNewUsers() {
     $guest = $this->insertGuestCustomer();
     $invalid_email = 'ivalid.@email.com';
     update_post_meta($guest['order_id'], '_billing_email', $invalid_email);
@@ -195,7 +195,7 @@ class WooCommerceTest extends \MailPoetTest  {
     $this->deleteOrder($guest['order_id']);
   }
 
-  function testItSynchronizesFirstNamesForRegisteredCustomers() {
+  public function testItSynchronizesFirstNamesForRegisteredCustomers() {
     $user = $this->insertRegisteredCustomerWithOrder(null, ['first_name' => '']);
     $this->woocommerce_segment->synchronizeCustomers();
     update_post_meta($user->order_id, '_billing_first_name', 'First name');
@@ -205,7 +205,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->first_name)->equals('First name (newer)');
   }
 
-  function testItSynchronizesLastNamesForRegisteredCustomers() {
+  public function testItSynchronizesLastNamesForRegisteredCustomers() {
     $user = $this->insertRegisteredCustomerWithOrder(null, ['last_name' => '']);
     $this->woocommerce_segment->synchronizeCustomers();
     update_post_meta($user->order_id, '_billing_last_name', 'Last name');
@@ -215,7 +215,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->last_name)->equals('Last name (newer)');
   }
 
-  function testItSynchronizesFirstNamesForGuestCustomers() {
+  public function testItSynchronizesFirstNamesForGuestCustomers() {
     $guest = $this->insertGuestCustomer(null, ['first_name' => '']);
     $this->woocommerce_segment->synchronizeCustomers();
     update_post_meta($guest['order_id'], '_billing_first_name', 'First name');
@@ -225,7 +225,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->first_name)->equals('First name (newer)');
   }
 
-  function testItSynchronizesLastNamesForGuestCustomers() {
+  public function testItSynchronizesLastNamesForGuestCustomers() {
     $guest = $this->insertGuestCustomer(null, ['last_name' => '']);
     $this->woocommerce_segment->synchronizeCustomers();
     update_post_meta($guest['order_id'], '_billing_last_name', 'Last name');
@@ -235,7 +235,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->last_name)->equals('Last name (newer)');
   }
 
-  function testItSynchronizesSegment() {
+  public function testItSynchronizesSegment() {
     $this->insertRegisteredCustomer();
     $this->insertRegisteredCustomer();
     $this->insertGuestCustomer();
@@ -247,7 +247,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscribers->count())->equals(4);
   }
 
-  function testItRemovesRegisteredCustomersFromTrash() {
+  public function testItRemovesRegisteredCustomersFromTrash() {
     $user = $this->insertRegisteredCustomer();
     $this->woocommerce_segment->synchronizeCustomers();
     $subscriber = Subscriber::where("email", $user->user_email)
@@ -262,7 +262,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->deleted_at)->null();
   }
 
-  function testItRemovesGuestCustomersFromTrash() {
+  public function testItRemovesGuestCustomersFromTrash() {
     $guest = $this->insertGuestCustomer();
     $this->woocommerce_segment->synchronizeCustomers();
     $subscriber = Subscriber::where("email", $guest['email'])
@@ -277,7 +277,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber->deleted_at)->null();
   }
 
-  function testItRemovesOrphanedSubscribers() {
+  public function testItRemovesOrphanedSubscribers() {
     $this->insertRegisteredCustomer();
     $this->insertGuestCustomer();
     $user = $this->insertRegisteredCustomerWithOrder();
@@ -293,7 +293,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscribers->count())->equals(2);
   }
 
-  function testItDoesntDeleteNonWCData() {
+  public function testItDoesntDeleteNonWCData() {
     $this->insertRegisteredCustomer();
     $this->insertGuestCustomer();
     // WP user
@@ -335,7 +335,7 @@ class WooCommerceTest extends \MailPoetTest  {
     $subscriber3->delete();
   }
 
-  function testItUnsubscribesSubscribersWithoutWCFlagFromWCSegment() {
+  public function testItUnsubscribesSubscribersWithoutWCFlagFromWCSegment() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'first_name' => 'Mike',
@@ -355,7 +355,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect(SubscriberSegment::findOne($association->id))->isEmpty();
   }
 
-  function testItUnsubscribesSubscribersWithoutEmailFromWCSegment() {
+  public function testItUnsubscribesSubscribersWithoutEmailFromWCSegment() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'first_name' => 'Mike',
@@ -376,7 +376,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect(SubscriberSegment::findOne($association->id))->isEmpty();
   }
 
-  function testItSetGlobalStatusUnsubscribedForUsersUnsyncedFromWooCommerceSegment() {
+  public function testItSetGlobalStatusUnsubscribedForUsersUnsyncedFromWooCommerceSegment() {
     $guest = $this->insertGuestCustomer();
     $subscriber = Subscriber::createOrUpdate([
       'first_name' => 'Mike',
@@ -397,7 +397,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber_after_update->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItDoesntSetGlobalStatusUnsubscribedIfUserHasMoreLists() {
+  public function testItDoesntSetGlobalStatusUnsubscribedIfUserHasMoreLists() {
     $guest = $this->insertGuestCustomer();
     $subscriber = Subscriber::createOrUpdate([
       'first_name' => 'Mike',
@@ -423,7 +423,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($subscriber_after_update->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItSubscribesSubscribersToWCListWhenSettingIsEnabled() {
+  public function testItSubscribesSubscribersToWCListWhenSettingIsEnabled() {
     $wc_segment = Segment::getWooCommerceSegment();
     $user1 = $this->insertRegisteredCustomer();
     $user2 = $this->insertRegisteredCustomer();
@@ -465,7 +465,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($association2_after_update->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItUnsubscribesSubscribersFromWCListWhenSettingIsDisabled() {
+  public function testItUnsubscribesSubscribersFromWCListWhenSettingIsDisabled() {
     $wc_segment = Segment::getWooCommerceSegment();
     $user1 = $this->insertRegisteredCustomer();
     $user2 = $this->insertRegisteredCustomer();
@@ -507,7 +507,7 @@ class WooCommerceTest extends \MailPoetTest  {
     expect($association2_after_update->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanData();
     $this->removeCustomerRole();
   }
diff --git a/tests/integration/Services/AuthorizedEmailsControllerTest.php b/tests/integration/Services/AuthorizedEmailsControllerTest.php
index f04a495155..7912e16892 100644
--- a/tests/integration/Services/AuthorizedEmailsControllerTest.php
+++ b/tests/integration/Services/AuthorizedEmailsControllerTest.php
@@ -19,12 +19,12 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItResetsAuthorisedEmailsErrorIfMssIsNotActive() {
+  public function testItResetsAuthorisedEmailsErrorIfMssIsNotActive() {
     $this->settings->set('installed_at', new Carbon());
     $this->settings->set(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING, 'Error');
     $controller = $this->getController($authorized_emails_from_api = null);
@@ -32,7 +32,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
   }
 
-  function testItSetsProperErrorForOldUsers() {
+  public function testItSetsProperErrorForOldUsers() {
     $this->settings->set('installed_at', '2018-03-04');
     $this->settings->set('sender.address', 'invalid@email.com');
     $this->setMailPoetSendingMethod();
@@ -41,7 +41,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->equals(['invalid_sender_address' => 'invalid@email.com']);
   }
 
-  function testItSetsProperErrorForInvalidDefaultSender() {
+  public function testItSetsProperErrorForInvalidDefaultSender() {
     $this->settings->set('installed_at', new Carbon());
     $this->settings->set('sender.address', 'invalid@email.com');
     $this->setMailPoetSendingMethod();
@@ -50,7 +50,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->equals(['invalid_sender_address' => 'invalid@email.com']);
   }
 
-  function testItSetEmptyErrorWhenDefaultSenderAddressIsCorrect() {
+  public function testItSetEmptyErrorWhenDefaultSenderAddressIsCorrect() {
     $this->settings->set('installed_at', new Carbon());
     $this->settings->set('sender.address', 'auth@email.com');
     $this->setMailPoetSendingMethod();
@@ -59,23 +59,23 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($this->settings->get(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING))->null();
   }
 
-  function testItSetErrorForScheduledNewsletterWithUnauthorizedSender() {
+  public function testItSetErrorForScheduledNewsletterWithUnauthorizedSender() {
     $this->checkUnauthorizedInNewsletter(Newsletter::TYPE_STANDARD, Newsletter::STATUS_SCHEDULED);
   }
 
-  function testItSetErrorForActiveWelcomeEmailUnauthorizedSender() {
+  public function testItSetErrorForActiveWelcomeEmailUnauthorizedSender() {
     $this->checkUnauthorizedInNewsletter(Newsletter::TYPE_WELCOME, Newsletter::STATUS_ACTIVE);
   }
 
-  function testItSetErrorForPostNotificationUnauthorizedSender() {
+  public function testItSetErrorForPostNotificationUnauthorizedSender() {
     $this->checkUnauthorizedInNewsletter(Newsletter::TYPE_NOTIFICATION, Newsletter::STATUS_ACTIVE);
   }
 
-  function testItSetErrorForAutomaticEmailUnauthorizedSender() {
+  public function testItSetErrorForAutomaticEmailUnauthorizedSender() {
     $this->checkUnauthorizedInNewsletter(Newsletter::TYPE_AUTOMATIC, Newsletter::STATUS_ACTIVE);
   }
 
-  function testItResetErrorWhenAllSendersAreCorrect() {
+  public function testItResetErrorWhenAllSendersAreCorrect() {
     $newsletter = Newsletter::createOrUpdate([
       'subject' => 'Subject',
       'status' => Newsletter::STATUS_ACTIVE,
@@ -99,7 +99,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($error)->null();
   }
 
-  function testItResetsUnauthorizedErrorInMailerLog() {
+  public function testItResetsUnauthorizedErrorInMailerLog() {
     $log = MailerLog::setError(MailerLog::getMailerLog(), MailerError::OPERATION_AUTHORIZATION, 'message');
     MailerLog::updateMailerLog($log);
     $this->settings->set('installed_at', new Carbon());
@@ -111,7 +111,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($error)->null();
   }
 
-  function testItDoesNotResetOtherErrorInMailerLog() {
+  public function testItDoesNotResetOtherErrorInMailerLog() {
     $log = MailerLog::setError(MailerLog::getMailerLog(), MailerError::OPERATION_SEND, 'message');
     MailerLog::updateMailerLog($log);
     $this->settings->set('installed_at', new Carbon());
@@ -123,7 +123,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     expect($error['operation'])->equals(MailerError::OPERATION_SEND);
   }
 
-  function testItDoesNotResetMailerLogItErrorPersists() {
+  public function testItDoesNotResetMailerLogItErrorPersists() {
     $log = MailerLog::setError(MailerLog::getMailerLog(), MailerError::OPERATION_AUTHORIZATION, 'message');
     MailerLog::updateMailerLog($log);
     $this->settings->set('installed_at', new Carbon());
@@ -175,7 +175,7 @@ class AuthorizedEmailsControllerTest extends \MailPoetTest {
     return new AuthorizedEmailsController($this->settings, $bridge_mock);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
   }
diff --git a/tests/integration/Services/BridgeTest.php b/tests/integration/Services/BridgeTest.php
index 617b654711..883e52ed9f 100644
--- a/tests/integration/Services/BridgeTest.php
+++ b/tests/integration/Services/BridgeTest.php
@@ -21,7 +21,7 @@ class BridgeTest extends \MailPoetTest {
   /** @var Bridge */
   private $bridge;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->valid_key = 'abcdefghijklmnopqrstuvwxyz';
     $this->invalid_key = '401' . $this->valid_key;
@@ -39,61 +39,61 @@ class BridgeTest extends \MailPoetTest {
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItChecksIfCurrentSendingMethodIsMailpoet() {
+  public function testItChecksIfCurrentSendingMethodIsMailpoet() {
     expect(Bridge::isMPSendingServiceEnabled())->false();
     $this->setMailPoetSendingMethod();
     expect(Bridge::isMPSendingServiceEnabled())->true();
   }
 
-  function testMPCheckReturnsFalseWhenMailerThrowsException() {
+  public function testMPCheckReturnsFalseWhenMailerThrowsException() {
     $this->settings->set(Mailer::MAILER_CONFIG_SETTING_NAME, '');
     expect(Bridge::isMPSendingServiceEnabled())->false();
   }
 
-  function testItChecksIfPremiumKeyIsSpecified() {
+  public function testItChecksIfPremiumKeyIsSpecified() {
     expect(Bridge::isPremiumKeySpecified())->false();
     $this->fillPremiumKey();
     expect(Bridge::isPremiumKeySpecified())->true();
   }
 
-  function testItInstantiatesDefaultAPI() {
+  public function testItInstantiatesDefaultAPI() {
     $this->bridge->api = null;
     $this->bridge->initApi(null);
     expect($this->bridge->api instanceof API)->true();
   }
 
-  function testItChecksValidMSSKey() {
+  public function testItChecksValidMSSKey() {
     $result = $this->bridge->checkMSSKey($this->valid_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_VALID);
   }
 
-  function testItChecksInvalidMSSKey() {
+  public function testItChecksInvalidMSSKey() {
     $result = $this->bridge->checkMSSKey($this->invalid_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_INVALID);
   }
 
-  function testItChecksExpiringMSSKey() {
+  public function testItChecksExpiringMSSKey() {
     $result = $this->bridge->checkMSSKey($this->expiring_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_EXPIRING);
     expect($result['data']['expire_at'])->notEmpty();
   }
 
-  function testItChecksAlreadyUsed() {
+  public function testItChecksAlreadyUsed() {
     $result = $this->bridge->checkMSSKey($this->used_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_ALREADY_USED);
   }
 
-  function testItChecksForbiddenEndpointMSSKey() {
+  public function testItChecksForbiddenEndpointMSSKey() {
     $result = $this->bridge->checkMSSKey($this->forbidden_endpoint_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_INVALID);
   }
 
-  function testItReturnsErrorStateOnEmptyAPIResponseCodeDuringMSSCheck() {
+  public function testItReturnsErrorStateOnEmptyAPIResponseCodeDuringMSSCheck() {
     $api = Stub::make(new API(null), ['checkMSSKey' => []], $this);
     $this->bridge->api = $api;
     $result = $this->bridge->checkMSSKey($this->valid_key);
@@ -101,7 +101,7 @@ class BridgeTest extends \MailPoetTest {
     expect($result['state'])->equals(Bridge::KEY_CHECK_ERROR);
   }
 
-  function testItStoresExpectedMSSKeyStates() {
+  public function testItStoresExpectedMSSKeyStates() {
     $states = [
       Bridge::KEY_VALID => $this->valid_key,
       Bridge::KEY_INVALID => $this->invalid_key,
@@ -115,7 +115,7 @@ class BridgeTest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotStoreErroneousOrUnexpectedMSSKeyStates() {
+  public function testItDoesNotStoreErroneousOrUnexpectedMSSKeyStates() {
     $states = [
       ['state' => Bridge::KEY_CHECK_ERROR],
       [],
@@ -127,38 +127,38 @@ class BridgeTest extends \MailPoetTest {
     }
   }
 
-  function testItChecksValidPremiumKey() {
+  public function testItChecksValidPremiumKey() {
     $result = $this->bridge->checkPremiumKey($this->valid_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_VALID);
   }
 
-  function testItChecksInvalidPremiumKey() {
+  public function testItChecksInvalidPremiumKey() {
     $result = $this->bridge->checkPremiumKey($this->invalid_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_INVALID);
   }
 
-  function testItChecksAlreadyUsedPremiumKey() {
+  public function testItChecksAlreadyUsedPremiumKey() {
     $result = $this->bridge->checkPremiumKey($this->used_premium_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_ALREADY_USED);
   }
 
-  function testItChecksForbiddenEndpointPremiumKey() {
+  public function testItChecksForbiddenEndpointPremiumKey() {
     $result = $this->bridge->checkPremiumKey($this->forbidden_endpoint_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_INVALID);
   }
 
-  function testItChecksExpiringPremiumKey() {
+  public function testItChecksExpiringPremiumKey() {
     $result = $this->bridge->checkPremiumKey($this->expiring_premium_key);
     expect($result)->notEmpty();
     expect($result['state'])->equals(Bridge::KEY_EXPIRING);
     expect($result['data']['expire_at'])->notEmpty();
   }
 
-  function testItReturnsErrorStateOnEmptyAPIResponseCodeDuringPremiumCheck() {
+  public function testItReturnsErrorStateOnEmptyAPIResponseCodeDuringPremiumCheck() {
     $api = Stub::make(new API(null), ['checkPremiumKey' => []], $this);
     $this->bridge->api = $api;
     $result = $this->bridge->checkPremiumKey($this->valid_key);
@@ -166,7 +166,7 @@ class BridgeTest extends \MailPoetTest {
     expect($result['state'])->equals(Bridge::KEY_CHECK_ERROR);
   }
 
-  function testItStoresExpectedPremiumKeyStates() {
+  public function testItStoresExpectedPremiumKeyStates() {
     $states = [
       Bridge::KEY_VALID => $this->valid_key,
       Bridge::KEY_INVALID => $this->invalid_key,
@@ -181,7 +181,7 @@ class BridgeTest extends \MailPoetTest {
     }
   }
 
-  function testItDoesNotStoreErroneousOrUnexpectedPremiumKeyStates() {
+  public function testItDoesNotStoreErroneousOrUnexpectedPremiumKeyStates() {
     $states = [
       ['state' => Bridge::KEY_CHECK_ERROR],
       [],
@@ -193,7 +193,7 @@ class BridgeTest extends \MailPoetTest {
     }
   }
 
-  function testItUpdatesSubscriberCount() {
+  public function testItUpdatesSubscriberCount() {
     // it performs update if the key is valid or expiring
     $result = [];
     $result['state'] = Bridge::KEY_VALID;
@@ -208,7 +208,7 @@ class BridgeTest extends \MailPoetTest {
     expect($updated)->null();
   }
 
-  function testItInvalidatesMSSKey() {
+  public function testItInvalidatesMSSKey() {
     $this->settings->set(
       Bridge::API_KEY_STATE_SETTING_NAME,
       ['state' => Bridge::KEY_VALID]
@@ -217,7 +217,7 @@ class BridgeTest extends \MailPoetTest {
     expect($this->getMSSKeyState())->equals(['state' => Bridge::KEY_INVALID]);
   }
 
-  function testItChecksAndStoresKeysOnSettingsSave() {
+  public function testItChecksAndStoresKeysOnSettingsSave() {
     $response = ['abc' => 'def'];
     $bridge = Stub::makeEmptyExcept(
       $this->bridge,
@@ -259,12 +259,12 @@ class BridgeTest extends \MailPoetTest {
     $bridge->onSettingsSave($settings);
   }
 
-  function testItPingsBridge() {
+  public function testItPingsBridge() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     expect(Bridge::pingBridge())->true();
   }
 
-  function testItAllowsChangingRequestTimeout() {
+  public function testItAllowsChangingRequestTimeout() {
     $wp_remote_post_args = [];
     $wp = Stub::make(new WPFunctions, [
       'wpRemotePost' => function() use (&$wp_remote_post_args) {
@@ -322,7 +322,7 @@ class BridgeTest extends \MailPoetTest {
     return $this->settings->get(Bridge::PREMIUM_KEY_STATE_SETTING_NAME);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Services/BridgeTestMockAPI.php b/tests/integration/Services/BridgeTestMockAPI.php
index cea56f041d..8df8349059 100644
--- a/tests/integration/Services/BridgeTestMockAPI.php
+++ b/tests/integration/Services/BridgeTestMockAPI.php
@@ -7,33 +7,33 @@ use MailPoetVendor\Carbon\Carbon;
 class BridgeTestMockAPI extends API {
   public $api_key;
 
-  function __construct($api_key) {
+  public function __construct($api_key) {
     $this->setKey($api_key);
   }
 
-  function checkMSSKey() {
+  public function checkMSSKey() {
     // if a key begins with these codes, return them
     $regex = '/^(expiring|401|402|403|503)/';
     $code = preg_match($regex, $this->api_key, $m) ? $m[1] : 200;
     return $this->processAPICheckResponse($code);
   }
 
-  function checkPremiumKey() {
+  public function checkPremiumKey() {
     // if a key begins with these codes, return them
     $regex = '/^(expiring|401|402|403|503)/';
     $code = preg_match($regex, $this->api_key, $m) ? $m[1] : 200;
     return $this->processPremiumResponse($code);
   }
 
-  function updateSubscriberCount($count) {
+  public function updateSubscriberCount($count) {
     return true;
   }
 
-  function setKey($api_key) {
+  public function setKey($api_key) {
     $this->api_key = $api_key;
   }
 
-  function getKey() {
+  public function getKey() {
     return $this->api_key;
   }
 
diff --git a/tests/integration/Settings/SettingsControllerTest.php b/tests/integration/Settings/SettingsControllerTest.php
index e781af60b9..a171357970 100644
--- a/tests/integration/Settings/SettingsControllerTest.php
+++ b/tests/integration/Settings/SettingsControllerTest.php
@@ -12,37 +12,37 @@ class SettingsControllerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $controller;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->controller = $this->di_container->get(SettingsController::class);
   }
 
-  function testItReturnsStoredValue() {
+  public function testItReturnsStoredValue() {
     $this->createOrUpdateSetting('test_key', 1);
     $this->controller->resetCache();
     $this->assertEquals(1, $this->controller->get('test_key'));
   }
 
-  function testItReturnsStoredNestedValue() {
+  public function testItReturnsStoredNestedValue() {
     $this->createOrUpdateSetting('test_key', serialize(['sub_key' => 'value']));
     $this->assertEquals('value', $this->controller->get('test_key.sub_key'));
   }
 
-  function testItReturnsNullForUnknownSetting() {
+  public function testItReturnsNullForUnknownSetting() {
     $this->assertEquals(null, $this->controller->get('test_key'));
     $this->assertEquals(null, $this->controller->get('test_key.sub_key'));
     $this->createOrUpdateSetting('test_key', serialize(['sub_key' => 'value']));
     $this->assertEquals(null, $this->controller->get('test_key.wrong_subkey'));
   }
 
-  function testItReturnsDefaultValueForUnknownSetting() {
+  public function testItReturnsDefaultValueForUnknownSetting() {
     $this->assertEquals('default', $this->controller->get('test_key', 'default'));
     $this->assertEquals('default', $this->controller->get('test_key.sub_key', 'default'));
     $this->createOrUpdateSetting('test_key', serialize(['sub_key' => 'value']));
     $this->assertEquals('default', $this->controller->get('test_key.wrong_subkey', 'default'));
   }
 
-  function testItCanFetchValuesFromDB() {
+  public function testItCanFetchValuesFromDB() {
     $this->assertEquals(null, $this->controller->fetch('test_key'));
     $this->assertEquals(null, $this->controller->fetch('test_key.sub_key'));
     $this->assertEquals('default', $this->controller->fetch('test_key.wrong_subkey', 'default'));
@@ -51,7 +51,7 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertEquals('value', $this->controller->fetch('test_key.sub_key', 'default'));
   }
 
-  function testItReturnsDefaultValueAsFallback() {
+  public function testItReturnsDefaultValueAsFallback() {
     $settings = Stub::make($this->controller, [
       'settings_repository' => $this->make(SettingsRepository::class, [
          'findOneByName' => null,
@@ -67,7 +67,7 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertEquals(1, $settings->get('default1.default2'));
   }
 
-  function testItCanReturnAllSettings() {
+  public function testItCanReturnAllSettings() {
     $this->createOrUpdateSetting('test_key1', 1);
     $this->createOrUpdateSetting('test_key2', 2);
     $all = $this->controller->getAll();
@@ -75,21 +75,21 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertEquals(2, $all['test_key2']);
   }
 
-  function testItCanSetAtTopLevel() {
+  public function testItCanSetAtTopLevel() {
     $this->controller->set('test_key', 1);
     $this->assertEquals(1, $this->controller->get('test_key'));
     $db_value = $this->getSettingValue('test_key');
     $this->assertEquals(1, $db_value);
   }
 
-  function testItCanSetAtNestedLevel() {
+  public function testItCanSetAtNestedLevel() {
     $this->controller->set('test_key.key1.key2', 1);
     $this->assertEquals(1, $this->controller->get('test_key.key1.key2'));
     $db_value = unserialize($this->getSettingValue('test_key'));
     $this->assertEquals(1, $db_value['key1']['key2']);
   }
 
-  function testItCanSetNUll() {
+  public function testItCanSetNUll() {
     $this->controller->set('test_key.key1.key2', 1);
     $this->assertEquals(1, $this->controller->get('test_key.key1.key2'));
     $this->controller->set('test_key.key1.key2', null);
@@ -98,7 +98,7 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertNull($db_value['key1']['key2']);
   }
 
-  function testItCanOverrideValueAndSetAtNestedLevel() {
+  public function testItCanOverrideValueAndSetAtNestedLevel() {
     $this->controller->set('test_key.key1', 1);
     $this->controller->set('test_key.key1.key2', 1);
     $this->assertEquals(1, $this->controller->get('test_key.key1.key2'));
@@ -106,7 +106,7 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertEquals(1, $db_value['key1']['key2']);
   }
 
-  function testItLoadsFromDbOnlyOnce() {
+  public function testItLoadsFromDbOnlyOnce() {
     $this->createOrUpdateSetting('test_key', 1);
     $this->assertEquals(1, $this->controller->get('test_key'));
     $this->createOrUpdateSetting('test_key', 2);
@@ -114,7 +114,7 @@ class SettingsControllerTest extends \MailPoetTest {
     $this->assertEquals(true, true);
   }
 
-  function _after() {
+  public function _after() {
     $table_name = $this->entity_manager->getClassMetadata(SettingEntity::class)->getTableName();
     $this->connection->executeUpdate('TRUNCATE ' . $table_name);
   }
diff --git a/tests/integration/Settings/UserFlagsControllerTest.php b/tests/integration/Settings/UserFlagsControllerTest.php
index ca2bab987b..4ea46d61be 100644
--- a/tests/integration/Settings/UserFlagsControllerTest.php
+++ b/tests/integration/Settings/UserFlagsControllerTest.php
@@ -19,7 +19,7 @@ class UserFlagsControllerTest extends \MailPoetTest {
   /** @var int */
   private $current_user_id;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cleanup();
 
@@ -46,7 +46,7 @@ class UserFlagsControllerTest extends \MailPoetTest {
     $this->createUserFlag($other_user_id, 'flag_2', 'other_value_2');
   }
 
-  function testItGetsFlagsOfCurrentUser() {
+  public function testItGetsFlagsOfCurrentUser() {
     expect($this->user_flags->get('flag_1'))->equals('value_1');
     expect($this->user_flags->get('flag_2'))->equals('default_value_2');
     expect($this->user_flags->getAll())->equals([
@@ -56,14 +56,14 @@ class UserFlagsControllerTest extends \MailPoetTest {
     ]);
   }
 
-  function testItLoadsDataOnlyOnceWhenNeeded() {
+  public function testItLoadsDataOnlyOnceWhenNeeded() {
     $this->updateUserFlag($this->current_user_id, 'flag_1', 'new_value_1');
     expect($this->user_flags->get('flag_1'))->equals('new_value_1');
     $this->updateUserFlag($this->current_user_id, 'flag_1', 'newer_value_1');
     expect($this->user_flags->get('flag_1'))->equals('new_value_1');
   }
 
-  function testItSetsNewFlagValue() {
+  public function testItSetsNewFlagValue() {
     expect($this->user_flags->get('flag_1'))->equals('value_1');
     $this->user_flags->set('flag_1', 'updated_value');
     expect($this->user_flags->get('flag_1'))->equals('updated_value');
@@ -74,7 +74,7 @@ class UserFlagsControllerTest extends \MailPoetTest {
     expect($flag->getValue())->equals('updated_value');
   }
 
-  function testItDeletesAFlag() {
+  public function testItDeletesAFlag() {
     expect($this->user_flags->get('flag_1'))->equals('value_1');
     $this->user_flags->delete('flag_1');
     expect($this->user_flags->get('flag_1'))->equals('default_value_1');
@@ -85,7 +85,7 @@ class UserFlagsControllerTest extends \MailPoetTest {
     expect($flag)->null();
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanup();
     WPFunctions::set(new WPFunctions);
   }
diff --git a/tests/integration/Statistics/GATrackingTest.php b/tests/integration/Statistics/GATrackingTest.php
index d15da95345..0da5141a9e 100644
--- a/tests/integration/Statistics/GATrackingTest.php
+++ b/tests/integration/Statistics/GATrackingTest.php
@@ -19,7 +19,7 @@ class GATrackingTest extends \MailPoetTest {
   /** @var string[] */
   private $rendered_newsletter;
 
-  function _before() {
+  public function _before() {
     $this->internal_host = 'newsletters.mailpoet.com';
     $this->ga_campaign = 'Spring email';
     $this->link = add_query_arg(['foo' => 'bar', 'baz' => 'xyz'], 'http://www.mailpoet.com/');
@@ -29,7 +29,7 @@ class GATrackingTest extends \MailPoetTest {
     ];
   }
 
-  function testItConditionallyAppliesGATracking() {
+  public function testItConditionallyAppliesGATracking() {
     // No process (empty GA campaign)
     $newsletter = Newsletter::createOrUpdate(['id' => 123]);
     $tracking = new GATracking();
@@ -42,7 +42,7 @@ class GATrackingTest extends \MailPoetTest {
     expect($result)->notEquals($this->rendered_newsletter);
   }
 
-  function testItGetsGACampaignFromParentNewsletterForPostNotifications() {
+  public function testItGetsGACampaignFromParentNewsletterForPostNotifications() {
     $tracking = new GATracking();
     $notification = Newsletter::create();
     $notification->hydrate([
@@ -60,7 +60,7 @@ class GATrackingTest extends \MailPoetTest {
     expect($result)->notEquals($this->rendered_newsletter);
   }
 
-  function testItCanAddGAParamsToLinks() {
+  public function testItCanAddGAParamsToLinks() {
     $tracking = new GATracking();
     $newsletter = Newsletter::createOrUpdate([
       'ga_campaign' => $this->ga_campaign,
@@ -70,7 +70,7 @@ class GATrackingTest extends \MailPoetTest {
     expect($result['html'])->contains('utm_campaign=' . urlencode($this->ga_campaign));
   }
 
-  function testItKeepsShorcodes() {
+  public function testItKeepsShorcodes() {
     $tracking = new GATracking();
     $newsletter = Newsletter::createOrUpdate([
       'ga_campaign' => $this->ga_campaign,
@@ -80,7 +80,7 @@ class GATrackingTest extends \MailPoetTest {
     expect($result['html'])->contains('email=[subscriber:email]');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
   }
 }
diff --git a/tests/integration/Statistics/Track/ClicksTest.php b/tests/integration/Statistics/Track/ClicksTest.php
index 5bf3039287..9fcd6fa5d3 100644
--- a/tests/integration/Statistics/Track/ClicksTest.php
+++ b/tests/integration/Statistics/Track/ClicksTest.php
@@ -25,7 +25,7 @@ class ClicksTest extends \MailPoetTest {
 
   private $settings_controller;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     // create newsletter
     $newsletter = Newsletter::create();
@@ -68,7 +68,7 @@ class ClicksTest extends \MailPoetTest {
     $this->clicks = new Clicks($this->settings_controller, new Cookies());
   }
 
-  function testItAbortsWhenTrackDataIsEmptyOrMissingLink() {
+  public function testItAbortsWhenTrackDataIsEmptyOrMissingLink() {
     // abort function should be called twice:
     $clicks = Stub::construct($this->clicks, [$this->settings_controller, new Cookies()], [
       'abort' => Expected::exactly(2),
@@ -81,7 +81,7 @@ class ClicksTest extends \MailPoetTest {
     $clicks->track($data);
   }
 
-  function testItDoesNotTrackEventsFromWpUserWhenPreviewIsEnabled() {
+  public function testItDoesNotTrackEventsFromWpUserWhenPreviewIsEnabled() {
     $data = $this->track_data;
     $data->subscriber->wp_user_id = 99;
     $data->preview = true;
@@ -93,7 +93,7 @@ class ClicksTest extends \MailPoetTest {
     expect(StatisticsOpens::findMany())->isEmpty();
   }
 
-  function testItTracksClickAndOpenEvent() {
+  public function testItTracksClickAndOpenEvent() {
     $data = $this->track_data;
     $clicks = Stub::construct($this->clicks, [$this->settings_controller, new Cookies()], [
       'redirectToUrl' => null,
@@ -103,14 +103,14 @@ class ClicksTest extends \MailPoetTest {
     expect(StatisticsOpens::findMany())->notEmpty();
   }
 
-  function testItRedirectsToUrlAfterTracking() {
+  public function testItRedirectsToUrlAfterTracking() {
     $clicks = Stub::construct($this->clicks, [$this->settings_controller, new Cookies()], [
       'redirectToUrl' => Expected::exactly(1),
     ], $this);
     $clicks->track($this->track_data);
   }
 
-  function testItIncrementsClickEventCount() {
+  public function testItIncrementsClickEventCount() {
     $clicks = Stub::construct($this->clicks, [$this->settings_controller, new Cookies()], [
       'redirectToUrl' => null,
     ], $this);
@@ -120,7 +120,7 @@ class ClicksTest extends \MailPoetTest {
     expect(StatisticsClicks::findMany()[0]->count)->equals(2);
   }
 
-  function testItConvertsShortcodesToUrl() {
+  public function testItConvertsShortcodesToUrl() {
     $link = $this->clicks->processUrl(
       '[link:newsletter_view_in_browser_url]',
       $this->newsletter,
@@ -131,7 +131,7 @@ class ClicksTest extends \MailPoetTest {
     expect($link)->contains('&endpoint=view_in_browser');
   }
 
-  function testItFailsToConvertsInvalidShortcodeToUrl() {
+  public function testItFailsToConvertsInvalidShortcodeToUrl() {
     $clicks = Stub::construct($this->clicks, [$this->settings_controller, new Cookies()], [
       'abort' => Expected::exactly(1),
     ], $this);
@@ -145,7 +145,7 @@ class ClicksTest extends \MailPoetTest {
     );
   }
 
-  function testItDoesNotConvertNonexistentShortcodeToUrl() {
+  public function testItDoesNotConvertNonexistentShortcodeToUrl() {
     $link = $this->clicks->processUrl(
       '[link:unknown_shortcode]',
       $this->newsletter,
@@ -156,7 +156,7 @@ class ClicksTest extends \MailPoetTest {
     expect($link)->equals('[link:unknown_shortcode]');
   }
 
-  function testItDoesNotConvertRegularUrls() {
+  public function testItDoesNotConvertRegularUrls() {
     $link = $this->clicks->processUrl(
       'http://example.com',
       $this->newsletter,
@@ -167,7 +167,7 @@ class ClicksTest extends \MailPoetTest {
     expect($link)->equals('http://example.com');
   }
 
-  function testItProcessesShortcodesInRegularUrls() {
+  public function testItProcessesShortcodesInRegularUrls() {
     $link = $this->clicks->processUrl(
       'http://example.com/?email=[subscriber:email]&newsletter_subject=[newsletter:subject]',
       $this->newsletter,
@@ -178,7 +178,7 @@ class ClicksTest extends \MailPoetTest {
     expect($link)->equals('http://example.com/?email=test@example.com&newsletter_subject=Subject');
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . NewsletterLink::$_table);
diff --git a/tests/integration/Statistics/Track/OpensTest.php b/tests/integration/Statistics/Track/OpensTest.php
index cc2eaaef1c..fe4310f18c 100644
--- a/tests/integration/Statistics/Track/OpensTest.php
+++ b/tests/integration/Statistics/Track/OpensTest.php
@@ -15,7 +15,7 @@ use MailPoet\Tasks\Sending as SendingTask;
 use MailPoetVendor\Idiorm\ORM;
 
 class OpensTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // create newsletter
     $newsletter = Newsletter::create();
@@ -46,7 +46,7 @@ class OpensTest extends \MailPoetTest {
     $this->opens = new Opens();
   }
 
-  function testItReturnsImageWhenTrackDataIsEmpty() {
+  public function testItReturnsImageWhenTrackDataIsEmpty() {
     $opens = Stub::make($this->opens, [
       'returnResponse' => Expected::exactly(1),
     ], $this);
@@ -54,7 +54,7 @@ class OpensTest extends \MailPoetTest {
     expect(StatisticsOpens::findMany())->isEmpty();
   }
 
-  function testItDoesNotTrackOpenEventFromWpUserWhenPreviewIsEnabled() {
+  public function testItDoesNotTrackOpenEventFromWpUserWhenPreviewIsEnabled() {
     $data = $this->track_data;
     $data->subscriber->wp_user_id = 99;
     $data->preview = true;
@@ -65,11 +65,11 @@ class OpensTest extends \MailPoetTest {
     expect(StatisticsOpens::findMany())->isEmpty();
   }
 
-  function testItReturnsNothingWhenImageDisplayIsDisabled() {
+  public function testItReturnsNothingWhenImageDisplayIsDisabled() {
     expect($this->opens->track($this->track_data, $display_image = false))->isEmpty();
   }
 
-  function testItTracksOpenEvent() {
+  public function testItTracksOpenEvent() {
     $opens = Stub::make($this->opens, [
       'returnResponse' => null,
     ], $this);
@@ -77,7 +77,7 @@ class OpensTest extends \MailPoetTest {
     expect(StatisticsOpens::findMany())->notEmpty();
   }
 
-  function testItDoesNotTrackRepeatedOpenEvents() {
+  public function testItDoesNotTrackRepeatedOpenEvents() {
     $opens = Stub::make($this->opens, [
       'returnResponse' => null,
     ], $this);
@@ -87,14 +87,14 @@ class OpensTest extends \MailPoetTest {
     expect(count(StatisticsOpens::findMany()))->equals(1);
   }
 
-  function testItReturnsImageAfterTracking() {
+  public function testItReturnsImageAfterTracking() {
     $opens = Stub::make($this->opens, [
       'returnResponse' => Expected::exactly(1),
     ], $this);
     $opens->track($this->track_data);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
diff --git a/tests/integration/Statistics/Track/UnsubscribesTest.php b/tests/integration/Statistics/Track/UnsubscribesTest.php
index 3266d84bd0..e0342b9b17 100644
--- a/tests/integration/Statistics/Track/UnsubscribesTest.php
+++ b/tests/integration/Statistics/Track/UnsubscribesTest.php
@@ -11,7 +11,7 @@ use MailPoet\Tasks\Sending as SendingTask;
 use MailPoetVendor\Idiorm\ORM;
 
 class UnsubscribesTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     // create newsletter
     $newsletter = Newsletter::create();
@@ -33,7 +33,7 @@ class UnsubscribesTest extends \MailPoetTest {
     $this->unsubscribes = new Unsubscribes();
   }
 
-  function testItTracksUnsubscribeEvent() {
+  public function testItTracksUnsubscribeEvent() {
     $this->unsubscribes->track(
       $this->newsletter->id,
       $this->subscriber->id,
@@ -42,7 +42,7 @@ class UnsubscribesTest extends \MailPoetTest {
     expect(count(StatisticsUnsubscribes::findMany()))->equals(1);
   }
 
-  function testItDoesNotTrackRepeatedUnsubscribeEvents() {
+  public function testItDoesNotTrackRepeatedUnsubscribeEvents() {
     for ($count = 0; $count <= 2; $count++) {
       $this->unsubscribes->track(
         $this->newsletter->id,
@@ -53,7 +53,7 @@ class UnsubscribesTest extends \MailPoetTest {
     expect(count(StatisticsUnsubscribes::findMany()))->equals(1);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Statistics/Track/WooCommercePurchasesTest.php b/tests/integration/Statistics/Track/WooCommercePurchasesTest.php
index bc3f8c9a23..881e6dd231 100644
--- a/tests/integration/Statistics/Track/WooCommercePurchasesTest.php
+++ b/tests/integration/Statistics/Track/WooCommercePurchasesTest.php
@@ -33,7 +33,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
   /** @var Cookies */
   private $cookies;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cleanup();
 
@@ -44,7 +44,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     $this->cookies = new Cookies();
   }
 
-  function testItDoesNotTrackPaymentForWrongSubscriber() {
+  public function testItDoesNotTrackPaymentForWrongSubscriber() {
     $click = $this->createClick($this->link, $this->subscriber, 3);
 
     // create 'wrong_click' for different subscriber that is newer than the correct 'click'
@@ -59,7 +59,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->click_id)->equals($click->id);
   }
 
-  function testItTracksPayment() {
+  public function testItTracksPayment() {
     $click = $this->createClick($this->link, $this->subscriber);
     $order_mock = $this->createOrderMock($this->subscriber->email);
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -75,7 +75,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->order_price_total)->equals($order_mock->get_total());
   }
 
-  function testItTracksPaymentForMultipleNewsletters() {
+  public function testItTracksPaymentForMultipleNewsletters() {
     $click_1 = $this->createClick($this->link, $this->subscriber);
 
     // create click in other newsletter
@@ -101,7 +101,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($stats_2->queue_id)->equals($queue->id);
   }
 
-  function testItTracksPaymentForMultipleOrders() {
+  public function testItTracksPaymentForMultipleOrders() {
     $this->createClick($this->link, $this->subscriber);
 
     // first order
@@ -117,7 +117,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(2);
   }
 
-  function testItTracksPaymentOnlyForLatestClick() {
+  public function testItTracksPaymentOnlyForLatestClick() {
     $this->createClick($this->link, $this->subscriber, 3);
     $this->createClick($this->link, $this->subscriber, 5);
     $latest_click = $this->createClick($this->link, $this->subscriber, 1);
@@ -130,7 +130,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->click_id)->equals($latest_click->id);
   }
 
-  function testItTracksPaymentOnlyOnce() {
+  public function testItTracksPaymentOnlyOnce() {
     $this->createClick($this->link, $this->subscriber);
     $order_mock = $this->createOrderMock($this->subscriber->email);
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -139,7 +139,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(1);
   }
 
-  function testItTracksPaymentOnlyOnceWhenNewClickAppears() {
+  public function testItTracksPaymentOnlyOnceWhenNewClickAppears() {
     $this->createClick($this->link, $this->subscriber, 5);
     $order_mock = $this->createOrderMock($this->subscriber->email);
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -150,7 +150,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(1);
   }
 
-  function testItDoesNotTrackPaymentWhenClickTooOld() {
+  public function testItDoesNotTrackPaymentWhenClickTooOld() {
     $this->createClick($this->link, $this->subscriber, 20);
     $order_mock = $this->createOrderMock($this->subscriber->email);
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -158,7 +158,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(0);
   }
 
-  function testItDoesNotTrackPaymentForDifferentEmail() {
+  public function testItDoesNotTrackPaymentForDifferentEmail() {
     $this->createClick($this->link, $this->subscriber);
     $order_mock = $this->createOrderMock('different.email@example.com');
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -166,7 +166,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(0);
   }
 
-  function testItDoesNotTrackPaymentWhenClickNewerThanOrder() {
+  public function testItDoesNotTrackPaymentWhenClickNewerThanOrder() {
     $this->createClick($this->link, $this->subscriber, 0);
     $order_mock = $this->createOrderMock($this->subscriber->email);
     $woocommerce_purchases = new WooCommercePurchases($this->createWooCommerceHelperMock($order_mock), $this->cookies);
@@ -174,7 +174,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect(count(StatisticsWooCommercePurchases::findMany()))->equals(0);
   }
 
-  function testItTracksPaymentForCorrectClickWhenClickNewerThanOrderExists() {
+  public function testItTracksPaymentForCorrectClickWhenClickNewerThanOrderExists() {
     $click = $this->createClick($this->link, $this->subscriber, 5);
     $this->createClick($this->link, $this->subscriber, 0); // wrong click, should not be tracked
 
@@ -186,7 +186,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->click_id)->equals($click->id);
   }
 
-  function testItTracksByCookie() {
+  public function testItTracksByCookie() {
     $order_email = 'order.email@example.com';
     $cookie_email = 'cookie.email@example.com';
     $this->createSubscriber($order_email);
@@ -206,7 +206,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->click_id)->equals($click->id);
   }
 
-  function testItDoesNotTrackByCookieWhenTrackedByOrder() {
+  public function testItDoesNotTrackByCookieWhenTrackedByOrder() {
     $order_email = 'order.email@example.com';
     $cookie_email = 'cookie.email@example.com';
     $order_email_subscriber = $this->createSubscriber($order_email);
@@ -229,7 +229,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     expect($purchase_stats[0]->click_id)->equals($order_email_click->id);
   }
 
-  function testItTracksByBothOrderAndCookieForDifferentNewsletters() {
+  public function testItTracksByBothOrderAndCookieForDifferentNewsletters() {
     $order_email = 'order.email@example.com';
     $cookie_email = 'cookie.email@example.com';
     $order_email_subscriber = $this->createSubscriber($order_email);
@@ -264,7 +264,7 @@ class WooCommercePurchasesTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     $this->cleanup();
   }
 
diff --git a/tests/integration/Subscribers/ConfirmationEmailMailerTest.php b/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
index c187d142f2..a165c08288 100644
--- a/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
+++ b/tests/integration/Subscribers/ConfirmationEmailMailerTest.php
@@ -15,7 +15,7 @@ use MailPoetVendor\Idiorm\ORM;
 
 class ConfirmationEmailMailerTest extends \MailPoetTest {
 
-  function testItSendsConfirmationEmail() {
+  public function testItSendsConfirmationEmail() {
     $subcription_url_facrory_mock = $this->createMock(SubscriptionUrlFactory::class);
     $subcription_url_facrory_mock->method('getConfirmationUrl')->willReturn('http://example.com');
 
@@ -62,7 +62,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     $sender->sendConfirmationEmail($subscriber);
   }
 
-  function testItSetsErrorsWhenConfirmationEmailCannotBeSent() {
+  public function testItSetsErrorsWhenConfirmationEmailCannotBeSent() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'first_name' => 'John',
@@ -89,7 +89,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     expect($subscriber->getErrors()[0])->equals('Something went wrong with your subscription. Please contact the website owner.');
   }
 
-  function testItDoesntSendWhenMSSIsActiveAndConfirmationEmailIsNotAuthorized() {
+  public function testItDoesntSendWhenMSSIsActiveAndConfirmationEmailIsNotAuthorized() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate([
       'first_name' => 'John',
@@ -116,7 +116,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     $settings->set(AuthorizedEmailsController::AUTHORIZED_EMAIL_ADDRESSES_ERROR_SETTING, null);
   }
 
-  function testItLimitsNumberOfConfirmationEmailsForNotLoggedInUser() {
+  public function testItLimitsNumberOfConfirmationEmailsForNotLoggedInUser() {
     wp_set_current_user(0);
     expect((new WPFunctions)->isUserLoggedIn())->false();
     $subscriber = Subscriber::create();
@@ -144,7 +144,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     expect($sender->sendConfirmationEmail($subscriber))->equals(false);
   }
 
-  function testItDoesNotLimitNumberOfConfirmationEmailsForLoggedInUser() {
+  public function testItDoesNotLimitNumberOfConfirmationEmailsForLoggedInUser() {
     wp_set_current_user(1);
     expect((new WPFunctions)->isUserLoggedIn())->true();
     $subscriber = Subscriber::create();
@@ -172,7 +172,7 @@ class ConfirmationEmailMailerTest extends \MailPoetTest {
     expect($sender->sendConfirmationEmail($subscriber))->equals(true);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Subscribers/ImportExport/Export/DefaultSubscribersGetterTest.php b/tests/integration/Subscribers/ImportExport/Export/DefaultSubscribersGetterTest.php
index b82c5c1a69..4216cff02c 100644
--- a/tests/integration/Subscribers/ImportExport/Export/DefaultSubscribersGetterTest.php
+++ b/tests/integration/Subscribers/ImportExport/Export/DefaultSubscribersGetterTest.php
@@ -11,7 +11,7 @@ use MailPoet\Subscribers\ImportExport\Export\DefaultSubscribersGetter;
 use MailPoetVendor\Idiorm\ORM;
 
 class DefaultSubscribersGetterTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->subscriber_fields = [
       'first_name' => 'First name',
@@ -120,7 +120,7 @@ class DefaultSubscribersGetterTest extends \MailPoetTest {
     }, $subscribers);
   }
 
-  function testItGetsSubscribersInOneSegment() {
+  public function testItGetsSubscribersInOneSegment() {
     $getter = new DefaultSubscribersGetter([1], 10);
     $subscribers = $getter->get();
     expect($this->filterSubscribersData($subscribers))->equals([
@@ -149,7 +149,7 @@ class DefaultSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function testItGetsSubscribersInMultipleSegments() {
+  public function testItGetsSubscribersInMultipleSegments() {
     $getter = new DefaultSubscribersGetter([1, 2], 10);
     $subscribers = $getter->get();
     expect($this->filterSubscribersData($subscribers))->equals([
@@ -198,7 +198,7 @@ class DefaultSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function testItGetsSubscribersInBatches() {
+  public function testItGetsSubscribersInBatches() {
     $getter = new DefaultSubscribersGetter([1, 2], 2);
     expect($this->filterSubscribersData($getter->get()))->equals([
       [
@@ -250,7 +250,7 @@ class DefaultSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function testItGetsSubscribersWithoutSegment() {
+  public function testItGetsSubscribersWithoutSegment() {
     $getter = new DefaultSubscribersGetter([0], 10);
     $subscribers = $getter->get();
     expect($this->filterSubscribersData($subscribers))->equals([
@@ -267,7 +267,7 @@ class DefaultSubscribersGetterTest extends \MailPoetTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Subscribers/ImportExport/Export/DynamicSubscribersGetterTest.php b/tests/integration/Subscribers/ImportExport/Export/DynamicSubscribersGetterTest.php
index d2504ef545..a0d589a8d7 100644
--- a/tests/integration/Subscribers/ImportExport/Export/DynamicSubscribersGetterTest.php
+++ b/tests/integration/Subscribers/ImportExport/Export/DynamicSubscribersGetterTest.php
@@ -11,7 +11,7 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoetVendor\Idiorm\ORM;
 
 class DynamicSubscribersGetterTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->subscriber_fields = [
       'first_name' => 'First name',
@@ -116,7 +116,7 @@ class DynamicSubscribersGetterTest extends \MailPoetTest {
     }, $subscribers);
   }
 
-  function testItGetsSubscribersInOneSegment() {
+  public function testItGetsSubscribersInOneSegment() {
     $getter = new DynamicSubscribersGetter([1], 10);
     $subscribers = $getter->get();
     expect($this->filterSubscribersData($subscribers))->equals([
@@ -145,7 +145,7 @@ class DynamicSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function testItGetsSubscribersInMultipleSegments() {
+  public function testItGetsSubscribersInMultipleSegments() {
     $getter = new DynamicSubscribersGetter([1, 2], 10);
     expect($this->filterSubscribersData($getter->get()))->equals([
       [
@@ -206,7 +206,7 @@ class DynamicSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function testItGetsSubscribersInBatches() {
+  public function testItGetsSubscribersInBatches() {
     $getter = new DynamicSubscribersGetter([1, 2], 2);
     expect($this->filterSubscribersData($getter->get()))->equals([
       [
@@ -272,7 +272,7 @@ class DynamicSubscribersGetterTest extends \MailPoetTest {
     expect($getter->get())->equals(false);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . CustomField::$_table);
diff --git a/tests/integration/Subscribers/ImportExport/Export/ExportTest.php b/tests/integration/Subscribers/ImportExport/Export/ExportTest.php
index b00f3a31ae..841a465c45 100644
--- a/tests/integration/Subscribers/ImportExport/Export/ExportTest.php
+++ b/tests/integration/Subscribers/ImportExport/Export/ExportTest.php
@@ -13,7 +13,7 @@ use MailPoet\Subscribers\ImportExport\Export\Export;
 use MailPoetVendor\Idiorm\ORM;
 
 class ExportTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->JSON_data = json_decode(file_get_contents(dirname(__FILE__) . '/ExportTestData.json'), true);
     $this->subscriber_fields = [
@@ -103,7 +103,7 @@ class ExportTest extends \MailPoetTest {
     $this->export = new Export($this->JSON_data);
   }
 
-  function testItCanConstruct() {
+  public function testItCanConstruct() {
     expect($this->export->export_format_option)
       ->equals('csv');
     expect($this->export->subscriber_fields)
@@ -139,14 +139,14 @@ class ExportTest extends \MailPoetTest {
     )->equals(1);
   }
 
-  function testItCanGetSubscriberCustomFields() {
+  public function testItCanGetSubscriberCustomFields() {
     $source = CustomField::where('name', $this->custom_fields_data[0]['name'])
       ->findOne();
     $target = $this->export->getSubscriberCustomFields();
     expect($target)->equals([$source->id => $source->name]);
   }
 
-  function testItCanFormatSubscriberFields() {
+  public function testItCanFormatSubscriberFields() {
     $formatted_subscriber_fields = $this->export->formatSubscriberFields(
       array_keys($this->subscriber_fields),
       $this->export->getSubscriberCustomFields()
@@ -155,7 +155,7 @@ class ExportTest extends \MailPoetTest {
       ->equals(array_values($this->subscriber_fields));
   }
 
-  function testItProperlyReturnsSubscriberCustomFields() {
+  public function testItProperlyReturnsSubscriberCustomFields() {
     $subscribers = $this->export->getSubscribers(0, 10);
     foreach ($subscribers as $subscriber) {
       if ($subscriber['email'] === $this->subscribers_data[1]) {
@@ -165,7 +165,7 @@ class ExportTest extends \MailPoetTest {
     }
   }
 
-  function testItCanGetSubscribers() {
+  public function testItCanGetSubscribers() {
     $this->export->default_subscribers_getter = new DefaultSubscribersGetter([1], 100);
     $subscribers = $this->export->getSubscribers();
     expect($subscribers)->count(2);
@@ -180,20 +180,20 @@ class ExportTest extends \MailPoetTest {
 
   }
 
-  function testItAlwaysGroupsSubscribersBySegments() {
+  public function testItAlwaysGroupsSubscribersBySegments() {
     $this->export->default_subscribers_getter = new DefaultSubscribersGetter([0, 1, 2], 100);
     $subscribers = $this->export->getSubscribers();
     expect($subscribers)->count(5);
   }
 
-  function testItCanGetSubscribersOnlyWithoutSegments() {
+  public function testItCanGetSubscribersOnlyWithoutSegments() {
     $this->export->default_subscribers_getter = new DefaultSubscribersGetter([0], 100);
     $subscribers = $this->export->getSubscribers();
     expect($subscribers)->count(1);
     expect($subscribers[0]['segment_name'])->equals('Not In Segment');
   }
 
-  function testItRequiresWritableExportFile() {
+  public function testItRequiresWritableExportFile() {
     try {
       $this->export->export_path = '/fake_folder';
       $this->export->process();
@@ -204,7 +204,7 @@ class ExportTest extends \MailPoetTest {
     }
   }
 
-  function testItCanProcess() {
+  public function testItCanProcess() {
     try {
       $this->export->export_file = $this->export->getExportFile('csv');
       $this->export->export_format_option = 'csv';
@@ -226,7 +226,7 @@ class ExportTest extends \MailPoetTest {
     expect($result['exportFileURL'])->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Subscribers/ImportExport/Import/ImportTest.php b/tests/integration/Subscribers/ImportExport/Import/ImportTest.php
index 224e3e52b2..cc586b1883 100644
--- a/tests/integration/Subscribers/ImportExport/Import/ImportTest.php
+++ b/tests/integration/Subscribers/ImportExport/Import/ImportTest.php
@@ -11,7 +11,7 @@ use MailPoet\Subscribers\ImportExport\Import\Import;
 use MailPoetVendor\Idiorm\ORM;
 
 class ImportTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     $custom_field = CustomField::create();
     $custom_field->name = 'country';
     $custom_field->type = 'text';
@@ -58,7 +58,7 @@ class ImportTest extends \MailPoetTest {
     );
   }
 
-  function testItConstructs() {
+  public function testItConstructs() {
     expect(is_array($this->import->subscribers_data))->true();
     expect($this->import->segments_ids)->equals($this->test_data['segments']);
     expect(is_array($this->import->subscribers_fields))->true();
@@ -68,7 +68,7 @@ class ImportTest extends \MailPoetTest {
     expect($this->import->updated_at)->notEmpty();
   }
 
-  function testItChecksForRequiredDataFields() {
+  public function testItChecksForRequiredDataFields() {
     $data = $this->test_data;
     // exception should be thrown when one or more fields do not exist
     unset($data['timestamp']);
@@ -82,7 +82,7 @@ class ImportTest extends \MailPoetTest {
     $this->import->validateImportData($this->test_data);
   }
 
-  function testItValidatesColumnNames() {
+  public function testItValidatesColumnNames() {
     $data = $this->test_data;
     $data['columns']['test) values ((ExtractValue(1,CONCAT(0x5c, (SELECT version())))))%23'] = true;
     try {
@@ -93,7 +93,7 @@ class ImportTest extends \MailPoetTest {
     }
   }
 
-  function testItValidatesSubscribersEmail() {
+  public function testItValidatesSubscribersEmail() {
     $validation_rules = ['email' => 'email'];
 
     // invalid email is removed from data object
@@ -114,7 +114,7 @@ class ImportTest extends \MailPoetTest {
     expect($result)->equals($data);
   }
 
-  function testItThrowsErrorWhenNoValidSubscribersAreFoundDuringImport() {
+  public function testItThrowsErrorWhenNoValidSubscribersAreFoundDuringImport() {
     $data = [
       'subscribers' => [
         [
@@ -142,7 +142,7 @@ class ImportTest extends \MailPoetTest {
     }
   }
 
-  function testItTransformsSubscribers() {
+  public function testItTransformsSubscribers() {
     $custom_field = $this->subscribers_custom_fields[0];
     expect($this->import->subscribers_data['first_name'][0])
       ->equals($this->test_data['subscribers'][0][0]);
@@ -154,7 +154,7 @@ class ImportTest extends \MailPoetTest {
       ->equals($this->test_data['subscribers'][0][3]);
   }
 
-  function testItSplitsSubscribers() {
+  public function testItSplitsSubscribers() {
     $subscribers_data = $this->subscribers_data;
     $subscribers_data_existing = [
       [
@@ -188,7 +188,7 @@ class ImportTest extends \MailPoetTest {
     expect($wp_users)->equals([$subscribers_data_existing[0]['wp_user_id']]);
   }
 
-  function testItAddsMissingRequiredFieldsToSubscribersObject() {
+  public function testItAddsMissingRequiredFieldsToSubscribersObject() {
     $data = [
       'subscribers' => [
         [
@@ -228,7 +228,7 @@ class ImportTest extends \MailPoetTest {
     expect($result['data']['created_at'][0])->equals($import->created_at);
   }
 
-  function testItGetsSubscriberFields() {
+  public function testItGetsSubscriberFields() {
     $data = [
       'one',
       'two',
@@ -242,7 +242,7 @@ class ImportTest extends \MailPoetTest {
       ]);
   }
 
-  function testItGetsCustomSubscribersFields() {
+  public function testItGetsCustomSubscribersFields() {
     $data = [
       'one',
       'two',
@@ -252,7 +252,7 @@ class ImportTest extends \MailPoetTest {
     expect($fields)->equals([39]);
   }
 
-  function testItAddsOrUpdatesSubscribers() {
+  public function testItAddsOrUpdatesSubscribers() {
     $subscribers_data = [
       'data' => $this->subscribers_data,
       'fields' => $this->subscribers_fields,
@@ -276,7 +276,7 @@ class ImportTest extends \MailPoetTest {
       ->equals($subscribers_data['data']['first_name'][1]);
   }
 
-  function testItDeletesTrashedSubscribers() {
+  public function testItDeletesTrashedSubscribers() {
     $subscribers_data = [
       'data' => $this->subscribers_data,
       'fields' => $this->subscribers_fields,
@@ -311,7 +311,7 @@ class ImportTest extends \MailPoetTest {
     expect(count($db_subscribers))->equals(1);
   }
 
-  function testItCreatesOrUpdatesCustomFields() {
+  public function testItCreatesOrUpdatesCustomFields() {
     $subscribers_data = [
       'data' => $this->subscribers_data,
       'fields' => $this->subscribers_fields,
@@ -345,7 +345,7 @@ class ImportTest extends \MailPoetTest {
       ->equals($subscribers_data['data'][$custom_field][1]);
   }
 
-  function testItAddsSubscribersToSegments() {
+  public function testItAddsSubscribersToSegments() {
     $subscribers_data = [
       'data' => $this->subscribers_data,
       'fields' => $this->subscribers_fields,
@@ -377,7 +377,7 @@ class ImportTest extends \MailPoetTest {
     }
   }
 
-  function testItDeletesExistingTrashedSubscribers() {
+  public function testItDeletesExistingTrashedSubscribers() {
     $subscribers_data = [
       'data' => $this->subscribers_data,
       'fields' => $this->subscribers_fields,
@@ -393,7 +393,7 @@ class ImportTest extends \MailPoetTest {
     );
   }
 
-  function testItUpdatesSubscribers() {
+  public function testItUpdatesSubscribers() {
     $result = $this->import->process();
     expect($result['updated'])->equals(0);
     $result = $this->import->process();
@@ -403,7 +403,7 @@ class ImportTest extends \MailPoetTest {
     expect($result['updated'])->equals(0);
   }
 
-  function testItDoesNotUpdateExistingSubscribersStatusWhenStatusColumnIsNotPresent() {
+  public function testItDoesNotUpdateExistingSubscribersStatusWhenStatusColumnIsNotPresent() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(
       [
@@ -418,7 +418,7 @@ class ImportTest extends \MailPoetTest {
     expect($updated_subscriber->status)->equals('unsubscribed');
   }
 
-  function testItDoesNotUpdateExistingSubscribersStatusWhenStatusColumnIsPresent() {
+  public function testItDoesNotUpdateExistingSubscribersStatusWhenStatusColumnIsPresent() {
     $data = $this->test_data;
     $data['columns']['status'] = ['index' => 4];
     $data['subscribers'][0][] = 'subscribed';
@@ -438,7 +438,7 @@ class ImportTest extends \MailPoetTest {
     expect($updated_subscriber->status)->equals('unsubscribed');
   }
 
-  function testItImportsNewsSubscribersWithAllAdditionalParameters() {
+  public function testItImportsNewsSubscribersWithAllAdditionalParameters() {
     $data = $this->test_data;
     $data['columns']['status'] = ['index' => 4];
     $data['subscribers'][0][] = 'unsubscribed';
@@ -462,7 +462,7 @@ class ImportTest extends \MailPoetTest {
     expect($new_subscribers[1]->last_subscribed_at)->equals($test_time);
   }
 
-  function testItDoesNotUpdateExistingSubscribersLastSubscribedAtWhenItIsPresent() {
+  public function testItDoesNotUpdateExistingSubscribersLastSubscribedAtWhenItIsPresent() {
     $data = $this->test_data;
     $data['columns']['last_subscribed_at'] = ['index' => 4];
     $data['subscribers'][0][] = '2018-12-12 12:12:00';
@@ -482,7 +482,7 @@ class ImportTest extends \MailPoetTest {
     expect($updated_subscriber->last_subscribed_at)->equals('2017-12-12 12:12:00');
   }
 
-  function testItRunsImport() {
+  public function testItRunsImport() {
     $result = $this->import->process();
     expect($result['created'])->equals(2);
     Subscriber::where('email', 'mary@jane.com')
@@ -506,7 +506,7 @@ class ImportTest extends \MailPoetTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php b/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
index c377d028b6..4a210cb3c2 100644
--- a/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
+++ b/tests/integration/Subscribers/ImportExport/ImportExportFactoryTest.php
@@ -9,7 +9,7 @@ use MailPoet\Models\SubscriberSegment;
 use MailPoet\Subscribers\ImportExport\ImportExportFactory;
 
 class ImportExportFactoryTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $segment_1 = Segment::createOrUpdate(['name' => 'Unconfirmed Segment']);
     $segment_2 = Segment::createOrUpdate(['name' => 'Confirmed Segment']);
@@ -47,7 +47,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     $this->exportFactory = new ImportExportFactory('export');
   }
 
-  function testItCanGetSegmentsWithSubscriberCount() {
+  public function testItCanGetSegmentsWithSubscriberCount() {
     $segments = $this->importFactory->getSegments();
     expect(count($segments))->equals(2);
     expect($segments[0]['name'])->equals('Confirmed Segment');
@@ -56,7 +56,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($segments[1]['subscriberCount'])->equals(0);
   }
 
-  function testItCanGetPublicSegmentsForImport() {
+  public function testItCanGetPublicSegmentsForImport() {
     $segments = $this->importFactory->getSegments();
     expect($segments[0]['subscriberCount'])->equals(1);
     expect($segments[1]['subscriberCount'])->equals(0);
@@ -77,7 +77,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($segments[1]['subscriberCount'])->equals(0);
   }
 
-  function testItCanGetPublicSegmentsForExport() {
+  public function testItCanGetPublicSegmentsForExport() {
     $segments = $this->exportFactory->getSegments();
     expect(count($segments))->equals(2);
     $subscriber = Subscriber::where('email', 'john@mailpoet.com')
@@ -88,7 +88,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect(count($segments))->equals(1);
   }
 
-  function testItCanGetSegmentsForExport() {
+  public function testItCanGetSegmentsForExport() {
     $segments = $this->exportFactory->getSegments();
     expect(count($segments))->equals(2);
 
@@ -98,7 +98,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($segments[1]['subscriberCount'])->equals(1);
   }
 
-  function testItCanGetSubscriberFields() {
+  public function testItCanGetSubscriberFields() {
     $subsriberFields = $this->importFactory->getSubscriberFields();
     $fields = [
       'email',
@@ -124,7 +124,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     }
   }
 
-  function testItCanFormatSubscriberFields() {
+  public function testItCanFormatSubscriberFields() {
     $formattedSubscriberFields =
       $this->importFactory->formatSubscriberFields(
         $this->importFactory->getSubscriberFields()
@@ -142,7 +142,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($formattedSubscriberFields[0]['custom'])->false();
   }
 
-  function testItCanGetSubscriberCustomFields() {
+  public function testItCanGetSubscriberCustomFields() {
     $subscriberCustomFields =
       $this->importFactory
         ->getSubscriberCustomFields();
@@ -150,7 +150,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
       ->equals('date');
   }
 
-  function testItCanFormatSubscriberCustomFields() {
+  public function testItCanFormatSubscriberCustomFields() {
     $formattedSubscriberCustomFields =
       $this->importFactory->formatSubscriberCustomFields(
         $this->importFactory->getSubscriberCustomFields()
@@ -168,7 +168,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($formattedSubscriberCustomFields[0]['custom'])->true();
   }
 
-  function testItCanFormatFieldsForSelect2Import() {
+  public function testItCanFormatFieldsForSelect2Import() {
     $ImportExportFactory = clone($this->importFactory);
     $select2FieldsWithoutCustomFields = [
       [
@@ -213,7 +213,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($formattedFieldsForSelect2)->equals($select2FieldsWithoutCustomFields);
   }
 
-  function testItCanFormatFieldsForSelect2Export() {
+  public function testItCanFormatFieldsForSelect2Export() {
     $ImportExportFactory = clone($this->exportFactory);
     $select2FieldsWithoutCustomFields = [
       [
@@ -258,7 +258,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     expect($formattedFieldsForSelect2)->equals($select2FieldsWithoutCustomFields);
   }
 
-  function testItCanBootStrapImport() {
+  public function testItCanBootStrapImport() {
     $import = clone($this->importFactory);
     $importMenu = $import->bootstrap();
     expect(count(json_decode($importMenu['segments'], true)))
@@ -275,7 +275,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
     );
   }
 
-  function testItCanBootStrapExport() {
+  public function testItCanBootStrapExport() {
     $export = clone($this->importFactory);
     $exportMenu = $export->bootstrap();
     expect(count(json_decode($exportMenu['segments'], true)))
@@ -285,7 +285,7 @@ class ImportExportFactoryTest extends \MailPoetTest {
       ->equals(3);
   }
 
-  function _after() {
+  public function _after() {
     Subscriber::deleteMany();
     Segment::deleteMany();
     SubscriberSegment::deleteMany();
diff --git a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporterTest.php b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporterTest.php
index b2ddf94ac1..6f47889be1 100644
--- a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporterTest.php
+++ b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewsletterClicksExporterTest.php
@@ -13,12 +13,12 @@ class NewsletterClicksExporterTest extends \MailPoetTest {
   /** @var NewsletterClicksExporter */
   private $exporter;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->exporter = new NewsletterClicksExporter();
   }
 
-  function testExportWorksWhenSubscriberNotFound() {
+  public function testExportWorksWhenSubscriberNotFound() {
     $result = $this->exporter->export('email.that@doesnt.exists');
     expect($result)->internalType('array');
     expect($result)->hasKey('data');
@@ -27,7 +27,7 @@ class NewsletterClicksExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportWorksForSubscriberWithNoNewsletters() {
+  public function testExportWorksForSubscriberWithNoNewsletters() {
     Subscriber::createOrUpdate([
       'email' => 'email.that@has.no.newsletters',
     ]);
@@ -39,7 +39,7 @@ class NewsletterClicksExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportReturnsData() {
+  public function testExportReturnsData() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'email@with.clicks',
     ]);
diff --git a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporterTest.php b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporterTest.php
index 50ab08dee5..5f9e761c04 100644
--- a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporterTest.php
+++ b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/NewslettersExporterTest.php
@@ -13,12 +13,12 @@ class NewslettersExporterTest extends \MailPoetTest {
   /** @var NewslettersExporter */
   private $exporter;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->exporter = new NewslettersExporter();
   }
 
-  function testExportWorksWhenSubscriberNotFound() {
+  public function testExportWorksWhenSubscriberNotFound() {
     $result = $this->exporter->export('email.that@doesnt.exists');
     expect($result)->internalType('array');
     expect($result)->hasKey('data');
@@ -27,7 +27,7 @@ class NewslettersExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportWorksForSubscriberWithNoNewsletters() {
+  public function testExportWorksForSubscriberWithNoNewsletters() {
     Subscriber::createOrUpdate([
       'email' => 'email.that@has.no.newsletters',
     ]);
@@ -39,7 +39,7 @@ class NewslettersExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportReturnsRenderedSubjects() {
+  public function testExportReturnsRenderedSubjects() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user@with.newsletters',
     ]);
@@ -64,7 +64,7 @@ class NewslettersExporterTest extends \MailPoetTest {
     expect($result['data'][0]['data'])->contains(['name' => 'Email subject', 'value' => 'Email Subject']);
   }
 
-  function testExportReturnsUrl() {
+  public function testExportReturnsUrl() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user1@with.newsletters',
     ]);
@@ -87,7 +87,7 @@ class NewslettersExporterTest extends \MailPoetTest {
     expect($result['data'][0]['data'][3]['value'])->contains('mailpoet_router&endpoint=view_in_browser&action=view&data=');
   }
 
-  function testExportOpens() {
+  public function testExportOpens() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'user21@with.newsletters',
     ]);
diff --git a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporterTest.php b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporterTest.php
index e3b221b3bc..e0230a620c 100644
--- a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporterTest.php
+++ b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SegmentsExporterTest.php
@@ -11,12 +11,12 @@ class SegmentsExporterTest extends \MailPoetTest {
   /** @var SegmentsExporter */
   private $exporter;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->exporter = new SegmentsExporter();
   }
 
-  function testExportWorksWhenSubscriberNotFound() {
+  public function testExportWorksWhenSubscriberNotFound() {
     $result = $this->exporter->export('email.that@doesnt.exists');
     expect($result)->internalType('array');
     expect($result)->hasKey('data');
@@ -25,7 +25,7 @@ class SegmentsExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportWorksForSubscriberWithNoSegments() {
+  public function testExportWorksForSubscriberWithNoSegments() {
     Subscriber::createOrUpdate([
       'email' => 'email.that@has.no.segments',
     ]);
@@ -37,7 +37,7 @@ class SegmentsExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportWorksForSubscriberWithSegments() {
+  public function testExportWorksForSubscriberWithSegments() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'email.that@has.some.segments',
     ]);
diff --git a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporterTest.php b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporterTest.php
index cc873563c3..80fffd1fef 100644
--- a/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporterTest.php
+++ b/tests/integration/Subscribers/ImportExport/PersonalDataExporters/SubscriberExporterTest.php
@@ -10,12 +10,12 @@ class SubscriberExporterTest extends \MailPoetTest {
   /** @var SubscriberExporter */
   private $exporter;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->exporter = new SubscriberExporter();
   }
 
-  function testExportWorksWhenSubscriberNotFound() {
+  public function testExportWorksWhenSubscriberNotFound() {
     $result = $this->exporter->export('email.that@doesnt.exists');
     expect($result)->internalType('array');
     expect($result)->hasKey('data');
@@ -24,7 +24,7 @@ class SubscriberExporterTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testExportSubscriberWithoutCustomFields() {
+  public function testExportSubscriberWithoutCustomFields() {
     Subscriber::createOrUpdate([
       'email' => 'email.that@has.no.custom.fields',
       'first_name' => 'John',
@@ -54,7 +54,7 @@ class SubscriberExporterTest extends \MailPoetTest {
     expect($result['data'][0]['data'])->equals($expected);
   }
 
-  function testExportSubscriberWithSource() {
+  public function testExportSubscriberWithSource() {
     Subscriber::createOrUpdate([
       'email' => 'email.with@source.com',
       'first_name' => 'John',
@@ -70,7 +70,7 @@ class SubscriberExporterTest extends \MailPoetTest {
     ]);
   }
 
-  function testExportSubscriberWithIPs() {
+  public function testExportSubscriberWithIPs() {
     Subscriber::createOrUpdate([
       'email' => 'email.that@has.ip.addresses',
       'first_name' => 'John',
@@ -86,7 +86,7 @@ class SubscriberExporterTest extends \MailPoetTest {
   }
 
 
-  function testExportSubscriberWithCustomField() {
+  public function testExportSubscriberWithCustomField() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'email.that@has.custom.fields',
     ]);
diff --git a/tests/integration/Subscribers/InactiveSubscribersControllerTest.php b/tests/integration/Subscribers/InactiveSubscribersControllerTest.php
index b59806e490..7478c052f5 100644
--- a/tests/integration/Subscribers/InactiveSubscribersControllerTest.php
+++ b/tests/integration/Subscribers/InactiveSubscribersControllerTest.php
@@ -26,7 +26,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
   const INACTIVITY_DAYS_THRESHOLD = 5;
   const PROCESS_BATCH_SIZE = 100;
 
-  function _before() {
+  public function _before() {
     $this->controller = new InactiveSubscribersController($this->di_container->get(SettingsRepository::class));
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
@@ -44,7 +44,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     parent::_before();
   }
 
-  function testItDeactivatesOldSubscribersWithUnopenedEmail() {
+  public function testItDeactivatesOldSubscribersWithUnopenedEmail() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $subscriber1 = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
@@ -60,7 +60,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber2->status)->equals(Subscriber::STATUS_INACTIVE);
   }
 
-  function testItDeactivatesLimitedAmountOfSubscribers() {
+  public function testItDeactivatesLimitedAmountOfSubscribers() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $subscriber1 = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
@@ -84,7 +84,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber2->status)->equals(Subscriber::STATUS_INACTIVE);
   }
 
-  function testItDoesNotDeactivateNewSubscriberWithUnopenedEmail() {
+  public function testItDoesNotDeactivateNewSubscriberWithUnopenedEmail() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $subscriber = $this->createSubscriber('s1@email.com', $completed_days_ago = 3);
@@ -96,7 +96,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivateNewlyResubscribedSubscriberWithUnopenedEmail() {
+  public function testItDoesNotDeactivateNewlyResubscribedSubscriberWithUnopenedEmail() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
@@ -110,7 +110,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivateSubscriberWithoutSentEmail() {
+  public function testItDoesNotDeactivateSubscriberWithoutSentEmail() {
     $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
     $result = $this->controller->markInactiveSubscribers(self::INACTIVITY_DAYS_THRESHOLD, self::PROCESS_BATCH_SIZE);
@@ -119,7 +119,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivateSubscriberWhoRecentlyOpenedEmail() {
+  public function testItDoesNotDeactivateSubscriberWhoRecentlyOpenedEmail() {
     list($task, $queue) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 2);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
     $this->addSubcriberToTask($subscriber, $task);
@@ -132,7 +132,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivateSubscriberWhoReceivedEmailRecently() {
+  public function testItDoesNotDeactivateSubscriberWhoReceivedEmailRecently() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 0);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
     $this->addSubcriberToTask($subscriber, $task);
@@ -142,7 +142,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivateSubscriberWhoReceivedEmailWhichWasNeverOpened() {
+  public function testItDoesNotDeactivateSubscriberWhoReceivedEmailWhichWasNeverOpened() {
     list($task) = $this->createCompletedSendingTask($completed_days_ago = 2);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10);
     $this->addSubcriberToTask($subscriber, $task);
@@ -152,7 +152,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotDeactivatesSubscribersWhenMP2MigrationHappenedWithinInterval() {
+  public function testItDoesNotDeactivatesSubscribersWhenMP2MigrationHappenedWithinInterval() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $this->createSetting(MP2Migrator::MIGRATION_COMPLETE_SETTING_KEY, true, (new Carbon())->subDays(3));
@@ -167,7 +167,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     $this->removeSetting(MP2Migrator::MIGRATION_COMPLETE_SETTING_KEY);
   }
 
-  function testItActivatesSubscriberWhoRecentlyOpenedEmail() {
+  public function testItActivatesSubscriberWhoRecentlyOpenedEmail() {
     list($task, $queue) = $this->createCompletedSendingTask($completed_days_ago = 2);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10, Subscriber::STATUS_INACTIVE);
     $this->addSubcriberToTask($subscriber, $task);
@@ -178,7 +178,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItActivatesLimitedNumberOfSubscribers() {
+  public function testItActivatesLimitedNumberOfSubscribers() {
     list($task, $queue) = $this->createCompletedSendingTask($completed_days_ago = 3);
     $subscriber1 = $this->createSubscriber('s1@email.com', $created_days_ago = 10, Subscriber::STATUS_INACTIVE);
     $subscriber2 = $this->createSubscriber('s2@email.com', $created_days_ago = 10, Subscriber::STATUS_INACTIVE);
@@ -203,7 +203,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber2->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotActivateOldSubscribersWithUnopenedEmail() {
+  public function testItDoesNotActivateOldSubscribersWithUnopenedEmail() {
     list($task) = $this->createCompletedSendingTask($completed_days_ago = 2);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10, Subscriber::STATUS_INACTIVE);
     $this->addSubcriberToTask($subscriber, $task);
@@ -213,7 +213,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_INACTIVE);
   }
 
-  function testItActivatesSubscribersWhenMP2MigrationHappenedWithinInterval() {
+  public function testItActivatesSubscribersWhenMP2MigrationHappenedWithinInterval() {
     list($task) = $this->createCompletedSendingTaskWithOneOpen($completed_days_ago = 3);
 
     $this->createSetting(MP2Migrator::MIGRATION_COMPLETE_SETTING_KEY, true, (new Carbon())->subDays(3));
@@ -228,7 +228,7 @@ class InactiveSubscribersControllerTest extends \MailPoetTest {
     $this->removeSetting(MP2Migrator::MIGRATION_COMPLETE_SETTING_KEY);
   }
 
-  function testItDoesReactivateInactiveSubscribers() {
+  public function testItDoesReactivateInactiveSubscribers() {
     list($task) = $this->createCompletedSendingTask($completed_days_ago = 2);
     $subscriber = $this->createSubscriber('s1@email.com', $created_days_ago = 10, Subscriber::STATUS_INACTIVE);
     $this->addSubcriberToTask($subscriber, $task);
diff --git a/tests/integration/Subscribers/LinkTokensTest.php b/tests/integration/Subscribers/LinkTokensTest.php
index a402c2ea87..f6566e64f8 100644
--- a/tests/integration/Subscribers/LinkTokensTest.php
+++ b/tests/integration/Subscribers/LinkTokensTest.php
@@ -10,12 +10,12 @@ class LinkTokensTest extends \MailPoetTest {
   /** @var LinkTokens */
   private $link_tokens;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->link_tokens = new LinkTokens;
   }
 
-  function testItGeneratesSubscriberToken() {
+  public function testItGeneratesSubscriberToken() {
     $subscriber1 = $this->makeSubscriber(['email' => 'demo1@fake.loc']);
     $subscriber2 = $this->makeSubscriber(['email' => 'demo2@fake.loc']);
     $token1 = $this->link_tokens->getToken($subscriber1);
@@ -25,14 +25,14 @@ class LinkTokensTest extends \MailPoetTest {
     expect($token1 != $token2)->equals(true);
   }
 
-  function testItGetsSubscriberToken() {
+  public function testItGetsSubscriberToken() {
     $subscriber1 = $this->makeSubscriber(['email' => 'demo1@fake.loc', 'link_token' => 'already-existing-token']);
     $subscriber2 = $this->makeSubscriber(['email' => 'demo2@fake.loc']);
     expect($this->link_tokens->getToken($subscriber1))->equals('already-existing-token');
     expect(strlen($this->link_tokens->getToken($subscriber2)))->equals(6);
   }
 
-  function testItVerifiesSubscriberToken() {
+  public function testItVerifiesSubscriberToken() {
     $subscriber = $this->makeSubscriber([
       'email' => 'demo@fake.loc',
     ]);
@@ -41,7 +41,7 @@ class LinkTokensTest extends \MailPoetTest {
     expect($this->link_tokens->verifyToken($subscriber, 'faketoken'))->false();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
   }
 
diff --git a/tests/integration/Subscribers/NewSubscriberNotificationMailerTest.php b/tests/integration/Subscribers/NewSubscriberNotificationMailerTest.php
index 0f4613fe63..db5c49cf18 100644
--- a/tests/integration/Subscribers/NewSubscriberNotificationMailerTest.php
+++ b/tests/integration/Subscribers/NewSubscriberNotificationMailerTest.php
@@ -22,7 +22,7 @@ class NewSubscriberNotificationMailerTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     $this->subscriber = Subscriber::create();
     $this->subscriber->email = 'subscriber@example.com';
     $this->segments = [Segment::create(), Segment::create()];
@@ -31,14 +31,14 @@ class NewSubscriberNotificationMailerTest extends \MailPoetTest {
     $this->settings = SettingsController::getInstance();
   }
 
-  function testItDoesNotSendIfNoSettings() {
+  public function testItDoesNotSendIfNoSettings() {
     $this->settings->set(NewSubscriberNotificationMailer::SETTINGS_KEY, null);
     $mailer = Stub::makeEmpty(Mailer::class, ['send' => Expected::never()], $this);
     $service = new NewSubscriberNotificationMailer($mailer, $this->di_container->get(Renderer::class), $this->di_container->get(SettingsController::class));
     $service->send($this->subscriber, $this->segments);
   }
 
-  function testItDoesNotSendIfSettingsDoesNotHaveEnabled() {
+  public function testItDoesNotSendIfSettingsDoesNotHaveEnabled() {
     $this->settings->set(NewSubscriberNotificationMailer::SETTINGS_KEY, []);
     $mailer = Stub::makeEmpty(Mailer::class, ['send' => Expected::never()], $this);
     $service = new NewSubscriberNotificationMailer($mailer, $this->di_container->get(Renderer::class), $this->di_container->get(SettingsController::class));
@@ -46,21 +46,21 @@ class NewSubscriberNotificationMailerTest extends \MailPoetTest {
   }
 
 
-  function testItDoesNotSendIfSettingsDoesNotHaveAddress() {
+  public function testItDoesNotSendIfSettingsDoesNotHaveAddress() {
     $this->settings->set(NewSubscriberNotificationMailer::SETTINGS_KEY, ['enabled' => false]);
     $mailer = Stub::makeEmpty(Mailer::class, ['send' => Expected::never()], $this);
     $service = new NewSubscriberNotificationMailer($mailer, $this->di_container->get(Renderer::class), $this->di_container->get(SettingsController::class));
     $service->send($this->subscriber, $this->segments);
   }
 
-  function testItDoesNotSendIfDisabled() {
+  public function testItDoesNotSendIfDisabled() {
     $this->settings->set(NewSubscriberNotificationMailer::SETTINGS_KEY, ['enabled' => false, 'address' => 'a@b.c']);
     $mailer = Stub::makeEmpty(Mailer::class, ['send' => Expected::never()], $this);
     $service = new NewSubscriberNotificationMailer($mailer, $this->di_container->get(Renderer::class), $this->di_container->get(SettingsController::class));
     $service->send($this->subscriber, $this->segments);
   }
 
-  function testItSends() {
+  public function testItSends() {
     $this->settings->set(NewSubscriberNotificationMailer::SETTINGS_KEY, ['enabled' => true, 'address' => 'a@b.c']);
 
     $mailer = Stub::makeEmpty(Mailer::class, [
@@ -88,7 +88,7 @@ class NewSubscriberNotificationMailerTest extends \MailPoetTest {
     $service->send($this->subscriber, $this->segments);
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
   }
 }
diff --git a/tests/integration/Subscribers/RequiredCustomFieldValidatorTest.php b/tests/integration/Subscribers/RequiredCustomFieldValidatorTest.php
index d523aaddda..6935347ef7 100644
--- a/tests/integration/Subscribers/RequiredCustomFieldValidatorTest.php
+++ b/tests/integration/Subscribers/RequiredCustomFieldValidatorTest.php
@@ -10,7 +10,7 @@ class RequiredCustomFieldValidatorTest extends \MailPoetTest {
 
   private $custom_field;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     ORM::raw_execute('TRUNCATE ' . CustomField::$_table);
     $this->custom_field = CustomField::createOrUpdate([
@@ -20,35 +20,35 @@ class RequiredCustomFieldValidatorTest extends \MailPoetTest {
     ]);
   }
 
-  function testItValidatesDataWithoutCustomField() {
+  public function testItValidatesDataWithoutCustomField() {
     $validator = new RequiredCustomFieldValidator();
     $this->setExpectedException('Exception');
     $validator->validate([]);
   }
 
-  function testItValidatesDataWithCustomFieldPassedAsId() {
+  public function testItValidatesDataWithCustomFieldPassedAsId() {
     $validator = new RequiredCustomFieldValidator();
     $validator->validate([$this->custom_field->id() => 'value']);
   }
 
-  function testItValidatesDataWithCustomFieldPassedAsCFId() {
+  public function testItValidatesDataWithCustomFieldPassedAsCFId() {
     $validator = new RequiredCustomFieldValidator();
     $validator->validate(['cf_' . $this->custom_field->id() => 'custom field']);
   }
 
-  function testItValidatesDataWithEmptyCustomField() {
+  public function testItValidatesDataWithEmptyCustomField() {
     $validator = new RequiredCustomFieldValidator();
     $this->setExpectedException('Exception');
     $validator->validate([$this->custom_field->id() => '']);
   }
 
-  function testItValidatesDataWithEmptyCustomFieldAsCFId() {
+  public function testItValidatesDataWithEmptyCustomFieldAsCFId() {
     $validator = new RequiredCustomFieldValidator();
     $this->setExpectedException('Exception');
     $validator->validate(['cf_' . $this->custom_field->id() => '']);
   }
 
-  function testItValidatesOnlyFieldPresentInForm() {
+  public function testItValidatesOnlyFieldPresentInForm() {
     CustomField::createOrUpdate([
       'name' => 'custom field 2',
       'type' => 'text',
diff --git a/tests/integration/Subscribers/SourceTest.php b/tests/integration/Subscribers/SourceTest.php
index ff30ff3647..2c623d6610 100644
--- a/tests/integration/Subscribers/SourceTest.php
+++ b/tests/integration/Subscribers/SourceTest.php
@@ -6,7 +6,7 @@ use MailPoet\Models\Subscriber;
 
 class SourceTest extends \MailPoetTest {
 
-  function testItDoesntOverrideSource() {
+  public function testItDoesntOverrideSource() {
     $subscriber = Subscriber::createOrUpdate([
       'source' => Source::FORM,
     ]);
@@ -14,7 +14,7 @@ class SourceTest extends \MailPoetTest {
     expect($updated_subscriber->source)->equals(Source::FORM);
   }
 
-  function testItDoesntAllowInvalidSource() {
+  public function testItDoesntAllowInvalidSource() {
     $subscriber = Subscriber::createOrUpdate([
       'source' => Source::UNKNOWN,
     ]);
@@ -22,13 +22,13 @@ class SourceTest extends \MailPoetTest {
     Source::setSource($subscriber, 'invalid source');
   }
 
-  function testItWorksWhenNoSourceIsSet() {
+  public function testItWorksWhenNoSourceIsSet() {
     $subscriber = Subscriber::createOrUpdate([]);
     $updated_subscriber = Source::setSource($subscriber, Source::FORM);
     expect($updated_subscriber->source)->equals(Source::FORM);
   }
 
-  function testItWorks() {
+  public function testItWorks() {
     $subscriber = Subscriber::createOrUpdate([
       'source' => Source::UNKNOWN,
     ]);
diff --git a/tests/integration/Subscribers/SubscriberActionsTest.php b/tests/integration/Subscribers/SubscriberActionsTest.php
index 33b9e5a38c..02a4b7341b 100644
--- a/tests/integration/Subscribers/SubscriberActionsTest.php
+++ b/tests/integration/Subscribers/SubscriberActionsTest.php
@@ -26,7 +26,7 @@ class SubscriberActionsTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->test_data = [
       'first_name' => 'John',
@@ -41,7 +41,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanSubscribe() {
+  public function testItCanSubscribe() {
     $segment = Segment::create();
     $segment->hydrate(['name' => 'List #1']);
     $segment->save();
@@ -65,7 +65,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     expect($subscriber->deleted_at)->equals(null);
   }
 
-  function testItSchedulesWelcomeNotificationUponSubscriptionWhenSubscriptionConfirmationIsDisabled() {
+  public function testItSchedulesWelcomeNotificationUponSubscriptionWhenSubscriptionConfirmationIsDisabled() {
     // create segment
     $segment = Segment::create();
     $segment->hydrate(['name' => 'List #1']);
@@ -110,7 +110,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     expect($scheduled_notification)->notEmpty();
   }
 
-  function testItDoesNotScheduleWelcomeNotificationUponSubscriptionWhenSubscriptionConfirmationIsEnabled() {
+  public function testItDoesNotScheduleWelcomeNotificationUponSubscriptionWhenSubscriptionConfirmationIsEnabled() {
     // create segment
     $segment = Segment::create();
     $segment->hydrate(['name' => 'List #1']);
@@ -155,7 +155,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     expect($scheduled_notification)->isEmpty();
   }
 
-  function testItCannotSubscribeWithReservedColumns() {
+  public function testItCannotSubscribeWithReservedColumns() {
     $segment = Segment::create();
     $segment->hydrate(['name' => 'List #1']);
     $segment->save();
@@ -193,7 +193,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     expect($subscriber->deleted_at)->equals(null);
   }
 
-  function testItOverwritesSubscriberDataWhenConfirmationIsDisabled() {
+  public function testItOverwritesSubscriberDataWhenConfirmationIsDisabled() {
     $original_setting_value = $this->settings->get('signup_confirmation.enabled');
     $this->settings->set('signup_confirmation.enabled', false);
 
@@ -240,7 +240,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     $this->settings->set('signup_confirmation.enabled', $original_setting_value);
   }
 
-  function testItStoresUnconfirmedSubscriberDataWhenConfirmationIsEnabled() {
+  public function testItStoresUnconfirmedSubscriberDataWhenConfirmationIsEnabled() {
     $original_setting_value = $this->settings->get('signup_confirmation.enabled');
     $this->settings->set('signup_confirmation.enabled', true);
 
@@ -309,7 +309,7 @@ class SubscriberActionsTest extends \MailPoetTest {
     $this->settings->set('signup_confirmation.enabled', $original_setting_value);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . Segment::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
diff --git a/tests/integration/Subscribers/SubscriberPersonalDataEraserTest.php b/tests/integration/Subscribers/SubscriberPersonalDataEraserTest.php
index 1ee81c3361..2cc3ca756d 100644
--- a/tests/integration/Subscribers/SubscriberPersonalDataEraserTest.php
+++ b/tests/integration/Subscribers/SubscriberPersonalDataEraserTest.php
@@ -12,7 +12,7 @@ class SubscriberPersonalDataEraserTest extends \MailPoetTest {
   /** @var SubscriberPersonalDataEraser */
   private $eraser;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->eraser = new SubscriberPersonalDataEraser();
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
@@ -20,7 +20,7 @@ class SubscriberPersonalDataEraserTest extends \MailPoetTest {
     ORM::raw_execute('TRUNCATE ' . SubscriberCustomField::$_table);
   }
 
-  function testExportWorksWhenSubscriberNotFound() {
+  public function testExportWorksWhenSubscriberNotFound() {
     $result = $this->eraser->erase('email.that@doesnt.exists');
     expect($result)->internalType('array');
     expect($result)->hasKey('items_removed');
@@ -29,7 +29,7 @@ class SubscriberPersonalDataEraserTest extends \MailPoetTest {
     expect($result['done'])->equals(true);
   }
 
-  function testItDeletesCustomFields() {
+  public function testItDeletesCustomFields() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'eraser.test.email.that@has.custom.fields',
     ]);
@@ -53,7 +53,7 @@ class SubscriberPersonalDataEraserTest extends \MailPoetTest {
 
   }
 
-  function testItDeletesSubscriberData() {
+  public function testItDeletesSubscriberData() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'subscriber@for.anon.test',
       'first_name' => 'John',
@@ -74,7 +74,7 @@ class SubscriberPersonalDataEraserTest extends \MailPoetTest {
     expect($subscriber_after->unconfirmed_data)->equals('');
   }
 
-  function testItDeletesSubscriberEmailAddress() {
+  public function testItDeletesSubscriberEmailAddress() {
     $subscriber = Subscriber::createOrUpdate([
       'email' => 'subscriber@for.anon.test',
     ]);
diff --git a/tests/integration/Subscription/CaptchaSessionTest.php b/tests/integration/Subscription/CaptchaSessionTest.php
index 41c476dfca..17e57f0a38 100644
--- a/tests/integration/Subscription/CaptchaSessionTest.php
+++ b/tests/integration/Subscription/CaptchaSessionTest.php
@@ -11,24 +11,24 @@ class CaptchaSessionTest extends \MailPoetTest {
   /** @var CaptchaSession */
   private $captcha_session;
 
-  function _before() {
+  public function _before() {
     $this->captcha_session = new CaptchaSession(new WPFunctions);
     $this->captcha_session->init(self::SESSION_ID);
   }
 
-  function testItCanStoreAndRetrieveFormData() {
+  public function testItCanStoreAndRetrieveFormData() {
     $form_data = ['email' => 'email@example.com'];
     $this->captcha_session->setFormData($form_data);
     expect($this->captcha_session->getFormData())->equals($form_data);
   }
 
-  function testItCanStoreAndRetrieveCaptchaHash() {
+  public function testItCanStoreAndRetrieveCaptchaHash() {
     $hash = '1234';
     $this->captcha_session->setCaptchaHash($hash);
     expect($this->captcha_session->getCaptchaHash())->equals($hash);
   }
 
-  function testItCanResetSessionData() {
+  public function testItCanResetSessionData() {
     $this->captcha_session->setFormData(['email' => 'email@example.com']);
     $this->captcha_session->setCaptchaHash('hash123');
     $this->captcha_session->reset();
@@ -36,7 +36,7 @@ class CaptchaSessionTest extends \MailPoetTest {
     expect($this->captcha_session->getCaptchaHash())->false();
   }
 
-  function testItAssociatesDataWithSession() {
+  public function testItAssociatesDataWithSession() {
     $hash = '1234';
     $this->captcha_session->setCaptchaHash($hash);
     expect($this->captcha_session->getCaptchaHash())->equals($hash);
diff --git a/tests/integration/Subscription/CaptchaTest.php b/tests/integration/Subscription/CaptchaTest.php
index 70ad336123..b2c953f7de 100644
--- a/tests/integration/Subscription/CaptchaTest.php
+++ b/tests/integration/Subscription/CaptchaTest.php
@@ -21,7 +21,7 @@ class CaptchaTest extends \MailPoetTest {
   /** @var CaptchaSession */
   private $captcha_session;
 
-  function _before() {
+  public function _before() {
     $cookies_mock = $this->createMock(Cookies::class);
     $cookies_mock->method('get')->willReturn('abcd');
     $this->captcha_session = new CaptchaSession(new Functions());
@@ -31,13 +31,13 @@ class CaptchaTest extends \MailPoetTest {
     $this->captcha_session->reset();
   }
 
-  function testItDoesNotRequireCaptchaForTheFirstSubscription() {
+  public function testItDoesNotRequireCaptchaForTheFirstSubscription() {
     $email = 'non-existent-subscriber@example.com';
     $result = $this->captcha->isRequired($email);
     expect($result)->equals(false);
   }
 
-  function testItRequiresCaptchaForRepeatedRecipient() {
+  public function testItRequiresCaptchaForRepeatedRecipient() {
     $subscriber = Subscriber::create();
     $subscriber->hydrate(Fixtures::get('subscriber_template'));
     $subscriber->count_confirmations = 1;
@@ -46,7 +46,7 @@ class CaptchaTest extends \MailPoetTest {
     expect($result)->equals(true);
   }
 
-  function testItRequiresCaptchaForRepeatedIPAddress() {
+  public function testItRequiresCaptchaForRepeatedIPAddress() {
     $ip = SubscriberIP::create();
     $ip->ip = '127.0.0.1';
     $ip->created_at = Carbon::now()->subMinutes(1);
@@ -56,14 +56,14 @@ class CaptchaTest extends \MailPoetTest {
     expect($result)->equals(true);
   }
 
-  function testItRendersImageAndStoresHashToSession() {
+  public function testItRendersImageAndStoresHashToSession() {
     expect($this->captcha_session->getCaptchaHash())->false();
     $image = $this->captcha->renderImage(null, null, self::CAPTCHA_SESSION_ID, true);
     expect($image)->notEmpty();
     expect($this->captcha_session->getCaptchaHash())->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     SubscriberIP::deleteMany();
   }
 }
diff --git a/tests/integration/Subscription/FormTest.php b/tests/integration/Subscription/FormTest.php
index ba7fc2888d..9264f6454e 100644
--- a/tests/integration/Subscription/FormTest.php
+++ b/tests/integration/Subscription/FormTest.php
@@ -23,7 +23,7 @@ class FormTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $this->settings->set('sender', [
@@ -73,7 +73,7 @@ class FormTest extends \MailPoetTest {
     $this->settings->set('signup_confirmation.enabled', false);
   }
 
-  function testItSubscribesAndRedirectsBackWithSuccessResponse() {
+  public function testItSubscribesAndRedirectsBackWithSuccessResponse() {
     $url_helper = Stub::make(UrlHelper::class, [
       'redirectBack' => function($params) {
         return $params;
@@ -86,7 +86,7 @@ class FormTest extends \MailPoetTest {
     expect($result['mailpoet_error'])->null();
   }
 
-  function testItSubscribesAndRedirectsToCustomUrlWithSuccessResponse() {
+  public function testItSubscribesAndRedirectsToCustomUrlWithSuccessResponse() {
     // update form with a redirect setting
     $form = $this->form;
     $form_settings = unserialize($form->settings);
@@ -108,7 +108,7 @@ class FormTest extends \MailPoetTest {
     expect($result)->regExp('/http.*?sample-post/i');
   }
 
-  function testItDoesNotSubscribeAndRedirectsBackWithErrorResponse() {
+  public function testItDoesNotSubscribeAndRedirectsBackWithErrorResponse() {
     // clear subscriber email so that subscription fails
     $request_data = $this->request_data;
     $request_data['data']['email'] = false;
@@ -124,7 +124,7 @@ class FormTest extends \MailPoetTest {
     expect($result['mailpoet_success'])->null();
   }
 
-  function testItDoesNotSubscribeAndRedirectsToRedirectUrlIfPresent() {
+  public function testItDoesNotSubscribeAndRedirectsToRedirectUrlIfPresent() {
     $redirect_url = 'http://test/';
     $url_helper = Stub::make(UrlHelper::class, [
       'redirectTo' => function($params) {
@@ -141,7 +141,7 @@ class FormTest extends \MailPoetTest {
     expect($result)->equals($redirect_url);
   }
 
-  function _after() {
+  public function _after() {
     wp_delete_post($this->post);
     ORM::raw_execute('TRUNCATE ' . SegmentModel::$_table);
     ORM::raw_execute('TRUNCATE ' . FormModel::$_table);
diff --git a/tests/integration/Subscription/PagesTest.php b/tests/integration/Subscription/PagesTest.php
index 3824084ca2..5b5fe777d2 100644
--- a/tests/integration/Subscription/PagesTest.php
+++ b/tests/integration/Subscription/PagesTest.php
@@ -25,7 +25,7 @@ class PagesTest extends \MailPoetTest {
   /** @var Subscriber */
   private $subscriber;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->subscriber = Subscriber::create();
     $this->subscriber->hydrate(Fixtures::get('subscriber_template'));
@@ -38,7 +38,7 @@ class PagesTest extends \MailPoetTest {
     $this->pages = ContainerWrapper::getInstance()->get(Pages::class);
   }
 
-  function testItConfirmsSubscription() {
+  public function testItConfirmsSubscription() {
     $new_subscriber_notification_sender = Stub::makeEmpty(NewSubscriberNotificationMailer::class, ['send' => Stub\Expected::once()]);
     $subscription = $this->pages->init($action = false, $this->test_data, false, false, $new_subscriber_notification_sender);
     $subscription->confirm();
@@ -46,7 +46,7 @@ class PagesTest extends \MailPoetTest {
     expect($confirmed_subscriber->status)->equals(Subscriber::STATUS_SUBSCRIBED);
   }
 
-  function testItDoesNotConfirmSubscriptionOnDuplicateAttempt() {
+  public function testItDoesNotConfirmSubscriptionOnDuplicateAttempt() {
     $new_subscriber_notification_sender = Stub::makeEmpty(NewSubscriberNotificationMailer::class, ['send' => Stub\Expected::once()]);
     $subscriber = $this->subscriber;
     $subscriber->status = Subscriber::STATUS_SUBSCRIBED;
@@ -55,7 +55,7 @@ class PagesTest extends \MailPoetTest {
     expect($subscription->confirm())->false();
   }
 
-  function testItSendsWelcomeNotificationUponConfirmingSubscription() {
+  public function testItSendsWelcomeNotificationUponConfirmingSubscription() {
     $new_subscriber_notification_sender = Stub::makeEmpty(NewSubscriberNotificationMailer::class, ['send' => Stub\Expected::once()]);
     $subscription = $this->pages->init($action = false, $this->test_data, false, false, $new_subscriber_notification_sender);
     // create segment
@@ -109,14 +109,14 @@ class PagesTest extends \MailPoetTest {
     expect($scheduled_notification)->notEmpty();
   }
 
-  function testItUnsubscribes() {
+  public function testItUnsubscribes() {
     $pages = $this->pages->init($action = 'unsubscribe', $this->test_data);
     $pages->unsubscribe();
     $updated_subscriber = Subscriber::findOne($this->subscriber->id);
     expect($updated_subscriber->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItDoesntUnsubscribeWhenPreviewing() {
+  public function testItDoesntUnsubscribeWhenPreviewing() {
     $this->test_data['preview'] = 1;
     $pages = $this->pages->init($action = 'unsubscribe', $this->test_data);
     $pages->unsubscribe();
@@ -124,7 +124,7 @@ class PagesTest extends \MailPoetTest {
     expect($updated_subscriber->status)->notEquals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Subscription/ThrottlingTest.php b/tests/integration/Subscription/ThrottlingTest.php
index c851059ab8..15b4e577a9 100644
--- a/tests/integration/Subscription/ThrottlingTest.php
+++ b/tests/integration/Subscription/ThrottlingTest.php
@@ -8,7 +8,7 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoetVendor\Carbon\Carbon;
 
 class ThrottlingTest extends \MailPoetTest {
-  function testItProgressivelyThrottlesSubscriptions() {
+  public function testItProgressivelyThrottlesSubscriptions() {
     $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
     expect(Throttling::throttle())->equals(false);
     expect(Throttling::throttle())->equals(60);
@@ -21,7 +21,7 @@ class ThrottlingTest extends \MailPoetTest {
     expect(Throttling::throttle())->equals(MINUTE_IN_SECONDS * pow(2, 10));
   }
 
-  function testItDoesNotThrottleIfDisabledByAHook() {
+  public function testItDoesNotThrottleIfDisabledByAHook() {
     $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
     $wp = new WPFunctions;
     $wp->addFilter('mailpoet_subscription_limit_enabled', '__return_false');
@@ -31,7 +31,7 @@ class ThrottlingTest extends \MailPoetTest {
     expect(Throttling::throttle())->greaterThan(0);
   }
 
-  function testItDoesNotThrottleForLoggedInUsers() {
+  public function testItDoesNotThrottleForLoggedInUsers() {
     $_SERVER['REMOTE_ADDR'] = '127.0.0.1';
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
@@ -41,7 +41,7 @@ class ThrottlingTest extends \MailPoetTest {
     expect(Throttling::throttle())->greaterThan(0);
   }
 
-  function testItPurgesOldSubscriberIps() {
+  public function testItPurgesOldSubscriberIps() {
     $ip = SubscriberIP::create();
     $ip->ip = '127.0.0.1';
     $ip->save();
@@ -56,7 +56,7 @@ class ThrottlingTest extends \MailPoetTest {
     expect(SubscriberIP::count())->equals(1);
   }
 
-  function testItConvertsSecondsToTimeString() {
+  public function testItConvertsSecondsToTimeString() {
     expect(Throttling::secondsToTimeString(122885))->equals('34 hours 8 minutes 5 seconds');
     expect(Throttling::secondsToTimeString(3660))->equals('1 hours 1 minutes');
     expect(Throttling::secondsToTimeString(3601))->equals('1 hours 1 seconds');
@@ -66,7 +66,7 @@ class ThrottlingTest extends \MailPoetTest {
     expect(Throttling::secondsToTimeString(59))->equals('59 seconds');
   }
 
-  function _after() {
+  public function _after() {
     SubscriberIP::deleteMany();
   }
 }
diff --git a/tests/integration/Subscription/UrlTest.php b/tests/integration/Subscription/UrlTest.php
index f869d927f5..460b7bfa28 100644
--- a/tests/integration/Subscription/UrlTest.php
+++ b/tests/integration/Subscription/UrlTest.php
@@ -23,7 +23,7 @@ class UrlTest extends \MailPoetTest {
   /** @var SettingsController */
   private $settings;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = SettingsController::getInstance();
     $referral_detector = new ReferralDetector(WPFunctions::get(), $this->settings);
@@ -33,7 +33,7 @@ class UrlTest extends \MailPoetTest {
     $this->url = new SubscriptionUrlFactory(WPFunctions::get(), $this->settings, new LinkTokens);
   }
 
-  function testItReturnsTheDefaultPageUrlIfNoPageIsSetInSettings() {
+  public function testItReturnsTheDefaultPageUrlIfNoPageIsSetInSettings() {
     $this->settings->delete('subscription');
 
     $url = $this->url->getCaptchaUrl('abc');
@@ -47,21 +47,21 @@ class UrlTest extends \MailPoetTest {
     expect($url)->contains('endpoint=subscription');
   }
 
-  function testItReturnsTheCaptchaUrl() {
+  public function testItReturnsTheCaptchaUrl() {
     $url = $this->url->getCaptchaUrl('abc');
     expect($url)->notNull();
     expect($url)->contains('action=captcha');
     expect($url)->contains('endpoint=subscription');
   }
 
-  function testItReturnsTheCaptchaImageUrl() {
+  public function testItReturnsTheCaptchaImageUrl() {
     $url = $this->url->getCaptchaImageUrl(250, 100, 'abc');
     expect($url)->notNull();
     expect($url)->contains('action=captchaImage');
     expect($url)->contains('endpoint=subscription');
   }
 
-  function testItReturnsTheConfirmationUrl() {
+  public function testItReturnsTheConfirmationUrl() {
     // preview
     $url = $this->url->getConfirmationUrl(null);
     expect($url)->notNull();
@@ -79,7 +79,7 @@ class UrlTest extends \MailPoetTest {
     $this->checkData($url);
   }
 
-  function testItReturnsTheManageSubscriptionUrl() {
+  public function testItReturnsTheManageSubscriptionUrl() {
     // preview
     $url = $this->url->getManageUrl(null);
     expect($url)->notNull();
@@ -97,7 +97,7 @@ class UrlTest extends \MailPoetTest {
     $this->checkData($url);
   }
 
-  function testItReturnsTheUnsubscribeUrl() {
+  public function testItReturnsTheUnsubscribeUrl() {
     // preview
     $url = $this->url->getUnsubscribeUrl(null);
     expect($url)->notNull();
@@ -125,7 +125,7 @@ class UrlTest extends \MailPoetTest {
     expect($data['token'])->notEmpty();
   }
 
-  function _after() {
+  public function _after() {
     $this->di_container->get(SettingsRepository::class)->truncate();
     Subscriber::deleteMany();
   }
diff --git a/tests/integration/Tasks/SendingTest.php b/tests/integration/Tasks/SendingTest.php
index 553d8137d3..ba6c9dd70a 100644
--- a/tests/integration/Tasks/SendingTest.php
+++ b/tests/integration/Tasks/SendingTest.php
@@ -12,7 +12,7 @@ use MailPoetVendor\Carbon\Carbon;
 use MailPoetVendor\Idiorm\ORM;
 
 class SendingTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter = $this->createNewNewsletter();
     $this->task = $this->createNewScheduledTask();
@@ -27,7 +27,7 @@ class SendingTest extends \MailPoetTest {
     ]);
   }
 
-  function testItCanBeConstructed() {
+  public function testItCanBeConstructed() {
     $sending = SendingTask::create();
     expect_that($sending instanceof SendingTask);
     expect_that($sending->queue() instanceof SendingQueue);
@@ -35,7 +35,7 @@ class SendingTest extends \MailPoetTest {
     expect_that($sending->taskSubscribers() instanceof Subscribers);
   }
 
-  function testItCanBeConstructedOnlyWithAProperTaskType() {
+  public function testItCanBeConstructedOnlyWithAProperTaskType() {
     $this->task->type = 'wrong_type';
     try {
       $sending = SendingTask::create($this->task, $this->queue);
@@ -45,20 +45,20 @@ class SendingTest extends \MailPoetTest {
     }
   }
 
-  function testItCanCreateManyFromTasks() {
+  public function testItCanCreateManyFromTasks() {
     $sendings = SendingTask::createManyFromTasks([$this->task]);
     expect($sendings)->notEmpty();
     $queue = $sendings[0]->queue();
     expect($queue->task_id)->equals($this->task->id);
   }
 
-  function testItCanBeCreatedFromQueue() {
+  public function testItCanBeCreatedFromQueue() {
     $sending = SendingTask::createFromQueue($this->queue);
     $task = $sending->task();
     expect($task->id)->equals($this->queue->task_id);
   }
 
-  function testItCanBeInitializedByNewsletterId() {
+  public function testItCanBeInitializedByNewsletterId() {
     $sending = SendingTask::getByNewsletterId($this->newsletter->id);
     $queue = $sending->queue();
     $task = $sending->task();
@@ -66,13 +66,13 @@ class SendingTest extends \MailPoetTest {
     expect($task->id)->equals($queue->task_id);
   }
 
-  function testItCanBeConvertedToArray() {
+  public function testItCanBeConvertedToArray() {
     $sending = $this->sending->asArray();
     expect($sending['id'])->equals($this->queue->id);
     expect($sending['task_id'])->equals($this->task->id);
   }
 
-  function testItSavesDataForUnderlyingModels() {
+  public function testItSavesDataForUnderlyingModels() {
     $newsletter_rendered_subject = 'Abc';
     $status = ScheduledTask::STATUS_PAUSED;
     $this->sending->status = $status;
@@ -84,38 +84,38 @@ class SendingTest extends \MailPoetTest {
     expect($queue->newsletter_rendered_subject)->equals($newsletter_rendered_subject);
   }
 
-  function testItDeletesUnderlyingModels() {
+  public function testItDeletesUnderlyingModels() {
     $this->sending->delete();
     expect(ScheduledTask::findOne($this->task->id))->equals(false);
     expect(SendingQueue::findOne($this->queue->id))->equals(false);
     expect(ScheduledTaskSubscriber::where('task_id', $this->task->id)->findMany())->isEmpty();
   }
 
-  function testItGetsSubscribers() {
+  public function testItGetsSubscribers() {
     expect($this->sending->getSubscribers())->equals([123, 456]);
   }
 
-  function testItSetsSubscribers() {
+  public function testItSetsSubscribers() {
     $subscriber_ids = [1, 2, 3];
     $this->sending->setSubscribers($subscriber_ids);
     expect($this->sending->getSubscribers())->equals($subscriber_ids);
     expect($this->sending->count_total)->equals(count($subscriber_ids));
   }
 
-  function testItRemovesSubscribers() {
+  public function testItRemovesSubscribers() {
     $subscriber_ids = [456];
     $this->sending->removeSubscribers($subscriber_ids);
     expect($this->sending->getSubscribers())->equals([123]);
     expect($this->sending->count_total)->equals(1);
   }
 
-  function testItRemovesAllSubscribers() {
+  public function testItRemovesAllSubscribers() {
     $this->sending->removeAllSubscribers();
     expect($this->sending->getSubscribers())->equals([]);
     expect($this->sending->count_total)->equals(0);
   }
 
-  function testItUpdatesProcessedSubscribers() {
+  public function testItUpdatesProcessedSubscribers() {
     expect($this->sending->count_to_process)->equals(2);
     expect($this->sending->count_processed)->equals(0);
     $subscriber_ids = [456];
@@ -124,7 +124,7 @@ class SendingTest extends \MailPoetTest {
     expect($this->sending->count_processed)->equals(1);
   }
 
-  function testItGetsScheduledQueues() {
+  public function testItGetsScheduledQueues() {
     $this->sending->status = ScheduledTask::STATUS_SCHEDULED;
     $this->sending->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'))->subHours(1);
     $this->sending->save();
@@ -140,7 +140,7 @@ class SendingTest extends \MailPoetTest {
     expect($tasks)->isEmpty();
   }
 
-  function testItGetsBatchOfScheduledQueues() {
+  public function testItGetsBatchOfScheduledQueues() {
     $this->_after();
     $amount = 5;
     for ($i = 0; $i < $amount + 3; $i += 1) {
@@ -149,13 +149,13 @@ class SendingTest extends \MailPoetTest {
     expect(SendingTask::getScheduledQueues($amount))->count($amount);
   }
 
-  function testItDoesNotGetPaused() {
+  public function testItDoesNotGetPaused() {
     $this->_after();
     $this->createNewSendingTask(['status' => ScheduledTask::STATUS_PAUSED]);
     expect(SendingTask::getScheduledQueues())->count(0);
   }
 
-  function testItGetsRunningQueues() {
+  public function testItGetsRunningQueues() {
     $this->sending->status = null;
     $this->sending->scheduled_at = Carbon::createFromTimestamp(current_time('timestamp'))->subHours(1);
     $this->sending->save();
@@ -171,7 +171,7 @@ class SendingTest extends \MailPoetTest {
     expect($tasks)->isEmpty();
   }
 
-  function testItGetsBatchOfRunningQueues() {
+  public function testItGetsBatchOfRunningQueues() {
     $this->_after();
     $amount = 5;
     for ($i = 0; $i < $amount + 3; $i += 1) {
@@ -180,7 +180,7 @@ class SendingTest extends \MailPoetTest {
     expect(SendingTask::getRunningQueues($amount))->count($amount);
   }
 
-  function testItGetsBatchOfRunningQueuesSortedByUpdatedTime() {
+  public function testItGetsBatchOfRunningQueuesSortedByUpdatedTime() {
     $this->_after();
 
     $sending1 = $this->createNewSendingTask(['status' => ScheduledTask::STATUS_SCHEDULED]);
@@ -199,7 +199,7 @@ class SendingTest extends \MailPoetTest {
     expect($queues[2]->task_id)->equals($sending2->id());
   }
 
-  function testItGetsBatchOfScheduledQueuesSortedByUpdatedTime() {
+  public function testItGetsBatchOfScheduledQueuesSortedByUpdatedTime() {
     $this->_after();
 
     $sending1 = $this->createNewSendingTask(['status' => null]);
@@ -218,19 +218,19 @@ class SendingTest extends \MailPoetTest {
     expect($queues[2]->task_id)->equals($sending2->id());
   }
 
-  function createNewNewsletter() {
+  public function createNewNewsletter() {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_STANDARD;
     return $newsletter->save();
   }
 
-  function createNewScheduledTask() {
+  public function createNewScheduledTask() {
     $task = ScheduledTask::create();
     $task->type = SendingTask::TASK_TYPE;
     return $task->save();
   }
 
-  function createNewSendingQueue($args = []) {
+  public function createNewSendingQueue($args = []) {
     $newsletter = isset($args['newsletter']) ? $args['newsletter'] : $this->createNewNewsletter();
     $task = isset($args['task']) ? $args['task'] : $this->createNewScheduledTask();
 
@@ -240,7 +240,7 @@ class SendingTest extends \MailPoetTest {
     return $queue->save();
   }
 
-  function createNewSendingTask($args = []) {
+  public function createNewSendingTask($args = []) {
     $task = isset($args['task']) ? $args['task'] : $this->createNewScheduledTask();
     $queue = isset($args['queue']) ? $args['queue'] : $this->createNewSendingQueue(['task' => $task]);
     $status = isset($args['status']) ? $args['status'] : null;
@@ -252,7 +252,7 @@ class SendingTest extends \MailPoetTest {
     return $sending->save();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
diff --git a/tests/integration/Tasks/StateTest.php b/tests/integration/Tasks/StateTest.php
index bfbbbdc1d0..e0866b1b4f 100644
--- a/tests/integration/Tasks/StateTest.php
+++ b/tests/integration/Tasks/StateTest.php
@@ -15,12 +15,12 @@ class StateTest extends \MailPoetTest {
   /** @var State */
   private $tasks_state;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->tasks_state = new State();
   }
 
-  function testItCanFetchBasicTasksData() {
+  public function testItCanFetchBasicTasksData() {
     $this->createNewScheduledTask(SendingTask::TASK_TYPE);
     $this->createNewScheduledTask(Migration::TASK_TYPE);
     $data = $this->tasks_state->getLatestTasks();
@@ -34,7 +34,7 @@ class StateTest extends \MailPoetTest {
     expect($data[0])->hasKey('newsletter');
   }
 
-  function testItCanFilterTasksByType() {
+  public function testItCanFilterTasksByType() {
     $this->createNewScheduledTask(SendingTask::TASK_TYPE);
     $this->createNewScheduledTask(Migration::TASK_TYPE);
     $data = $this->tasks_state->getLatestTasks(Migration::TASK_TYPE);
@@ -42,7 +42,7 @@ class StateTest extends \MailPoetTest {
     expect($data[0]['type'])->equals(Migration::TASK_TYPE);
   }
 
-  function testItCanFilterTasksByStatus() {
+  public function testItCanFilterTasksByStatus() {
     $this->createNewScheduledTask(SendingTask::TASK_TYPE, ScheduledTask::STATUS_COMPLETED);
     $this->createNewScheduledTask(SendingTask::TASK_TYPE, ScheduledTask::STATUS_PAUSED);
     $data = $this->tasks_state->getLatestTasks(null, [ScheduledTask::STATUS_COMPLETED]);
@@ -50,7 +50,7 @@ class StateTest extends \MailPoetTest {
     expect($data[0]['status'])->equals(ScheduledTask::STATUS_COMPLETED);
   }
 
-  function testItFetchesNewsletterDataForSendingTasks() {
+  public function testItFetchesNewsletterDataForSendingTasks() {
     $task = $this->createNewScheduledTask(SendingTask::TASK_TYPE);
     $newsletter = $this->createNewNewsletter();
     $this->createNewSendingQueue($task->id, $newsletter->id, 'Rendered Subject');
@@ -61,7 +61,7 @@ class StateTest extends \MailPoetTest {
     expect($data[0]['newsletter']['preview_url'])->notEmpty();
   }
 
-  function testItDoesNotFailForSendingTaskWithMissingNewsletterInconsistentData() {
+  public function testItDoesNotFailForSendingTaskWithMissingNewsletterInconsistentData() {
     $task = $this->createNewScheduledTask(SendingTask::TASK_TYPE);
     $this->createNewSendingQueue($task->id);
     $data = $this->tasks_state->getLatestTasks();
@@ -71,27 +71,27 @@ class StateTest extends \MailPoetTest {
     expect($data[0]['newsletter']['preview_url'])->equals(null);
   }
 
-  function testItDoesNotFailForSendingTaskWithoutQueue() {
+  public function testItDoesNotFailForSendingTaskWithoutQueue() {
     $this->createNewScheduledTask(SendingTask::TASK_TYPE);
     $data = $this->tasks_state->getLatestTasks();
     expect(count($data))->equals(1);
   }
 
-  function createNewScheduledTask($type, $status = ScheduledTask::STATUS_COMPLETED) {
+  public function createNewScheduledTask($type, $status = ScheduledTask::STATUS_COMPLETED) {
     $task = ScheduledTask::create();
     $task->type = $type;
     $task->status = $status;
     return $task->save();
   }
 
-  function createNewNewsletter($subject = 'Test Subject') {
+  public function createNewNewsletter($subject = 'Test Subject') {
     $newsletter = Newsletter::create();
     $newsletter->type = Newsletter::TYPE_STANDARD;
     $newsletter->subject = $subject;
     return $newsletter->save();
   }
 
-  function createNewSendingQueue($task_id, $newsletter_id = null, $rendered_subject = null) {
+  public function createNewSendingQueue($task_id, $newsletter_id = null, $rendered_subject = null) {
     $queue = SendingQueue::create();
     $queue->newsletter_id = $newsletter_id;
     $queue->task_id = $task_id;
@@ -99,7 +99,7 @@ class StateTest extends \MailPoetTest {
     return $queue->save();
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Newsletter::$_table);
     ORM::raw_execute('TRUNCATE ' . ScheduledTask::$_table);
     ORM::raw_execute('TRUNCATE ' . SendingQueue::$_table);
diff --git a/tests/integration/Tasks/Subscribers/BatchIteratorTest.php b/tests/integration/Tasks/Subscribers/BatchIteratorTest.php
index 86834b8097..ba70e94f20 100644
--- a/tests/integration/Tasks/Subscribers/BatchIteratorTest.php
+++ b/tests/integration/Tasks/Subscribers/BatchIteratorTest.php
@@ -7,7 +7,7 @@ use MailPoet\Tasks\Subscribers\BatchIterator;
 use MailPoetVendor\Idiorm\ORM;
 
 class BatchIteratorTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->task_id = 123; // random ID
     $this->batch_size = 2;
@@ -21,7 +21,7 @@ class BatchIteratorTest extends \MailPoetTest {
     $this->iterator = new BatchIterator($this->task_id, $this->batch_size);
   }
 
-  function testItFailsToConstructWithWrongArguments() {
+  public function testItFailsToConstructWithWrongArguments() {
     try {
       $iterator = new BatchIterator(0, 0);
       $this->fail('Exception was not thrown');
@@ -30,12 +30,12 @@ class BatchIteratorTest extends \MailPoetTest {
     }
   }
 
-  function testItConstructs() {
+  public function testItConstructs() {
     $iterator = new BatchIterator(123, 456); // random IDs
     expect_that($iterator instanceof BatchIterator);
   }
 
-  function testItIterates() {
+  public function testItIterates() {
     $iterations = ceil($this->subscriber_count / $this->batch_size);
     $i = 0;
     foreach ($this->iterator as $batch) {
@@ -57,11 +57,11 @@ class BatchIteratorTest extends \MailPoetTest {
     expect($i)->equals($iterations);
   }
 
-  function testItCanBeCounted() {
+  public function testItCanBeCounted() {
     expect(count($this->iterator))->equals($this->subscriber_count);
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . ScheduledTaskSubscriber::$_table);
   }
 }
diff --git a/tests/integration/Twig/AssetsTest.php b/tests/integration/Twig/AssetsTest.php
index 5e9cc2d494..b5c95caa0b 100644
--- a/tests/integration/Twig/AssetsTest.php
+++ b/tests/integration/Twig/AssetsTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Twig;
 use MailPoet\Twig\Assets;
 
 class AssetsTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->assets_url = 'https://www.testing.com/wp-content/plugins/mailpoet/assets';
     $this->version = '1.2.3';
@@ -19,7 +19,7 @@ class AssetsTest extends \MailPoetTest {
     );
   }
 
-  function testItGeneratesJavascriptTagsForAssetsUsinManifestFile() {
+  public function testItGeneratesJavascriptTagsForAssetsUsinManifestFile() {
     $manifest = [
       'script1.js' => 'script1.hash.js',
       'script2.js' => 'script2.hash.js',
@@ -40,7 +40,7 @@ class AssetsTest extends \MailPoetTest {
     );
   }
 
-  function testItGeneratesJavascriptTagsForAssetsWhenManifestFileDoesNotExist() {
+  public function testItGeneratesJavascriptTagsForAssetsWhenManifestFileDoesNotExist() {
     expect($this->assets_extension->generateJavascript('lib/script1.js', 'script2.js'))->equals(
       '<script type="text/javascript" src="' . $this->assets_url . '/js/lib/script1.js"></script>'
       . "\n"
@@ -48,7 +48,7 @@ class AssetsTest extends \MailPoetTest {
     );
   }
 
-  function testItGeneratesStylesheetTagsForAssetsUsingManifestFile() {
+  public function testItGeneratesStylesheetTagsForAssetsUsingManifestFile() {
     $manifest = [
       'style1.css' => 'style1.hash.css',
       'style2.css' => 'style2.hash.css',
@@ -69,7 +69,7 @@ class AssetsTest extends \MailPoetTest {
     );
   }
 
-  function testItGeneratesStylesheetTagsWhenManifestFileDoesNotExist() {
+  public function testItGeneratesStylesheetTagsWhenManifestFileDoesNotExist() {
     expect($this->assets_extension->generateStylesheet('style1.css', 'style2.css'))->equals(
       '<link rel="stylesheet" type="text/css" href="' . $this->assets_url . '/dist/css/style1.css" />'
       . "\n"
@@ -77,13 +77,13 @@ class AssetsTest extends \MailPoetTest {
     );
   }
 
-  function testItGeneratesImageUrls() {
+  public function testItGeneratesImageUrls() {
     expect($this->assets_extension->generateImageUrl('image1.png'))->equals(
       $this->assets_url . '/img/image1.png?mailpoet_version=' . $this->version
     );
   }
 
-  function testItAppendsVersionToUrl() {
+  public function testItAppendsVersionToUrl() {
     $without_file = 'http://url.com/';
     expect($this->assets_extension->appendVersionToUrl($without_file))->equals(
       $without_file . '?mailpoet_version=' . $this->version
diff --git a/tests/integration/Twig/FunctionsTest.php b/tests/integration/Twig/FunctionsTest.php
index 3389512063..c8921afae5 100644
--- a/tests/integration/Twig/FunctionsTest.php
+++ b/tests/integration/Twig/FunctionsTest.php
@@ -7,7 +7,7 @@ use MailPoet\Twig\Functions;
 use MailPoet\WP\Functions as WPFunctions;
 
 class FunctionsTest extends \MailPoetTest {
-  function testItExecutesIsRtlFunction() {
+  public function testItExecutesIsRtlFunction() {
     $template = ['template' => '{% if is_rtl() %}rtl{% endif %}'];
     $twig = new \MailPoetVendor\Twig_Environment(new \MailPoetVendor\Twig_Loader_Array($template));
     WPFunctions::set(Stub::make(new WPFunctions, [
@@ -21,7 +21,7 @@ class FunctionsTest extends \MailPoetTest {
     expect($result_no_rtl)->isEmpty();
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/integration/Util/ConflictResolverTest.php b/tests/integration/Util/ConflictResolverTest.php
index c40a207618..e180e24f21 100644
--- a/tests/integration/Util/ConflictResolverTest.php
+++ b/tests/integration/Util/ConflictResolverTest.php
@@ -9,7 +9,7 @@ class ConflictResolverTest extends \MailPoetTest {
   public $conflict_resolver;
   public $wp_filter;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->conflict_resolver = new ConflictResolver();
     $this->conflict_resolver->init();
@@ -17,7 +17,7 @@ class ConflictResolverTest extends \MailPoetTest {
     $this->wp_filter = $wp_filter;
   }
 
-  function testItResolvesRouterUrlQueryParametersConflict() {
+  public function testItResolvesRouterUrlQueryParametersConflict() {
     expect(!empty($this->wp_filter['mailpoet_conflict_resolver_router_url_query_parameters']))->true();
     // it should unset action & endpoint GET variables
     $_GET['endpoint'] = $_GET['action'] = $_GET['test'] = 'test';
@@ -27,7 +27,7 @@ class ConflictResolverTest extends \MailPoetTest {
     expect(empty($_GET['test']))->false();
   }
 
-  function testItUnloadsAllStylesFromLocationsNotOnPermittedList() {
+  public function testItUnloadsAllStylesFromLocationsNotOnPermittedList() {
     expect(!empty($this->wp_filter['mailpoet_conflict_resolver_styles']))->true();
     // grab a random permitted style location
     $permitted_asset_location = $this->conflict_resolver->permitted_assets_locations['styles'][array_rand($this->conflict_resolver->permitted_assets_locations['styles'], 1)];
@@ -45,7 +45,7 @@ class ConflictResolverTest extends \MailPoetTest {
     expect(in_array('permitted_style', $wp_styles->queue))->true();
   }
 
-  function testItWhitelistsStyles() {
+  public function testItWhitelistsStyles() {
     wp_enqueue_style('select2', '/wp-content/some/offending/plugin/select2.css');
     $wp = new WPFunctions;
     $wp->addFilter(
@@ -65,7 +65,7 @@ class ConflictResolverTest extends \MailPoetTest {
     expect(in_array('select2', $wp_styles->queue))->true();
   }
 
-  function testItUnloadsAllScriptsFromLocationsNotOnPermittedList() {
+  public function testItUnloadsAllScriptsFromLocationsNotOnPermittedList() {
     expect(!empty($this->wp_filter['mailpoet_conflict_resolver_scripts']))->true();
     // grab a random permitted script location
     $permitted_asset_location = $this->conflict_resolver->permitted_assets_locations['scripts'][array_rand($this->conflict_resolver->permitted_assets_locations['scripts'], 1)];
@@ -83,7 +83,7 @@ class ConflictResolverTest extends \MailPoetTest {
     expect(in_array('permitted_script', $wp_scripts->queue))->true();
   }
 
-  function testItWhitelistsScripts() {
+  public function testItWhitelistsScripts() {
     wp_enqueue_script('select2', '/wp-content/some/offending/plugin/select2.js');
     $wp = new WPFunctions;
     $wp->addFilter(
@@ -101,6 +101,6 @@ class ConflictResolverTest extends \MailPoetTest {
     expect(in_array('select2', $wp_scripts->queue))->true();
   }
 
-  function _after() {
+  public function _after() {
   }
 }
\ No newline at end of file
diff --git a/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php b/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
index b44bffb4a9..8ac45635a2 100644
--- a/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
+++ b/tests/integration/Util/Notices/InactiveSubscribersNoticeTest.php
@@ -11,7 +11,7 @@ use MailPoet\WP\Functions as WPFunctions;
 use MailPoetVendor\Idiorm\ORM;
 
 class InactiveSubscribersNoticeTest extends \MailPoetTest {
-  function testItDisplays() {
+  public function testItDisplays() {
     $this->createSubscribers(50);
 
     $notice = new InactiveSubscribersNotice(SettingsController::getInstance(), new WPFunctions());
@@ -21,7 +21,7 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
     expect($result)->contains('<a href="admin.php?page=mailpoet-settings#advanced" class="button button-primary">Go to the Advanced Settings</a>');
   }
 
-  function testItDoesntDisplayWhenDisabled() {
+  public function testItDoesntDisplayWhenDisabled() {
     $this->createSubscribers(50);
 
     $notice = new InactiveSubscribersNotice(SettingsController::getInstance(), new WPFunctions());
@@ -30,7 +30,7 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItDoesntDisplayWhenInactiveTimeRangeChanged() {
+  public function testItDoesntDisplayWhenInactiveTimeRangeChanged() {
     $this->createSubscribers(50);
 
     $settings_factory = new Settings();
@@ -41,7 +41,7 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function testItDoesntDisplayWhenNotEnoughInactiveSubscribers() {
+  public function testItDoesntDisplayWhenNotEnoughInactiveSubscribers() {
     $this->createSubscribers(49);
 
     $notice = new InactiveSubscribersNotice(SettingsController::getInstance(), new WPFunctions());
@@ -49,12 +49,12 @@ class InactiveSubscribersNoticeTest extends \MailPoetTest {
     expect($result)->null();
   }
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->cleanup();
   }
 
-  function _after() {
+  public function _after() {
     parent::_after();
     $this->cleanup();
   }
diff --git a/tests/integration/Util/Notices/PHPVersionWarningsTest.php b/tests/integration/Util/Notices/PHPVersionWarningsTest.php
index 9a2f9a36fc..12bc4b54c8 100644
--- a/tests/integration/Util/Notices/PHPVersionWarningsTest.php
+++ b/tests/integration/Util/Notices/PHPVersionWarningsTest.php
@@ -7,45 +7,45 @@ class PHPVersionWarningsTest extends \MailPoetTest {
   /** @var PHPVersionWarnings */
   private $phpVersionWarning;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->phpVersionWarning = new PHPVersionWarnings();
     delete_transient('dismissed-php-version-outdated-notice');
   }
 
-  function _after() {
+  public function _after() {
     delete_transient('dismissed-php-version-outdated-notice');
   }
 
-  function testPHP55IsOutdated() {
+  public function testPHP55IsOutdated() {
     expect($this->phpVersionWarning->isOutdatedPHPVersion('5.5.3'))->true();
   }
 
-  function testPHP56IsOutdated() {
+  public function testPHP56IsOutdated() {
     expect($this->phpVersionWarning->isOutdatedPHPVersion('5.6.3'))->true();
   }
 
-  function testPHP72IsNotOutdated() {
+  public function testPHP72IsNotOutdated() {
     expect($this->phpVersionWarning->isOutdatedPHPVersion('7.2'))->false();
   }
 
-  function testItPrintsWarningFor56() {
+  public function testItPrintsWarningFor56() {
     $warning = $this->phpVersionWarning->init('5.6.3', true);
     expect($warning->getMessage())->contains('Your website is running on PHP 5.6.3');
     expect($warning->getMessage())->contains('https://www.mailpoet.com/let-us-handle-your-php-upgrade/');
   }
 
-  function testItPrintsNoWarningFor70() {
+  public function testItPrintsNoWarningFor70() {
     $warning = $this->phpVersionWarning->init('7.0', true);
     expect($warning)->null();
   }
 
-  function testItPrintsNoWarningWhenDisabled() {
+  public function testItPrintsNoWarningWhenDisabled() {
     $warning = $this->phpVersionWarning->init('5.5.3', false);
     expect($warning)->null();
   }
 
-  function testItPrintsNoWarningWhenDismised() {
+  public function testItPrintsNoWarningWhenDismised() {
     $this->phpVersionWarning->init('5.5.3', true);
     $this->phpVersionWarning->disable();
     $warning = $this->phpVersionWarning->init('5.5.3', true);
diff --git a/tests/integration/WP/EmojiTest.php b/tests/integration/WP/EmojiTest.php
index 367f2ddc50..5a36020073 100644
--- a/tests/integration/WP/EmojiTest.php
+++ b/tests/integration/WP/EmojiTest.php
@@ -8,7 +8,7 @@ use MailPoet\WP\Emoji;
 use MailPoetVendor\Idiorm\ORM;
 
 class EmojiTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->data_encoded = "Emojis: &#x1f603;&#x1f635;&#x1f4aa;, not emojis: &#046;&#0142;";
     $this->data_decoded = "Emojis: 😃😵💪, not emojis: &#046;&#0142;";
@@ -17,7 +17,7 @@ class EmojiTest extends \MailPoetTest {
     $this->emoji = new Emoji();
   }
 
-  function testItCanEncodeNewsletterRenderedBody() {
+  public function testItCanEncodeNewsletterRenderedBody() {
     $emoji = $this->make(
       Emoji::class,
       ['encodeForUTF8Column' => Expected::exactly(3, function ($params) {
@@ -29,7 +29,7 @@ class EmojiTest extends \MailPoetTest {
     $emoji->encodeEmojisInBody('string, call 3');
   }
 
-  function testItCanDecodeNewsletterBody() {
+  public function testItCanDecodeNewsletterBody() {
     $emoji = $this->make(
       Emoji::class,
       ['decodeEntities' => Expected::exactly(3, function ($params) {
@@ -41,7 +41,7 @@ class EmojiTest extends \MailPoetTest {
     $emoji->decodeEmojisInBody('string, call 3');
   }
 
-  function testItCanEncodeForUTF8Column() {
+  public function testItCanEncodeForUTF8Column() {
     $table = Env::$db_prefix . 'dummytable_utf8';
     $this->createTable($table, 'utf8');
 
@@ -51,7 +51,7 @@ class EmojiTest extends \MailPoetTest {
     $this->dropTable($table);
   }
 
-  function testItDoesNotEncodeForUTF8MB4Column() {
+  public function testItDoesNotEncodeForUTF8MB4Column() {
     $table = Env::$db_prefix . 'dummytable_utf8mb4';
     $this->createTable($table, 'utf8mb4');
 
@@ -61,7 +61,7 @@ class EmojiTest extends \MailPoetTest {
     $this->dropTable($table);
   }
 
-  function testItCanDecodeEntities() {
+  public function testItCanDecodeEntities() {
     $result = $this->emoji->decodeEntities($this->data_encoded);
     expect($result)->equals($this->data_decoded);
   }
diff --git a/tests/integration/WP/FunctionsTest.php b/tests/integration/WP/FunctionsTest.php
index 6eb0acbd78..9a833db0d7 100644
--- a/tests/integration/WP/FunctionsTest.php
+++ b/tests/integration/WP/FunctionsTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\WP;
 use MailPoet\WP\Functions as WPFunctions;
 
 class FunctionsTest extends \MailPoetTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     global $content_width;
     $this->_content_width = $content_width;
@@ -15,7 +15,7 @@ class FunctionsTest extends \MailPoetTest {
     $this->wp = new WPFunctions;
   }
 
-  function makeAttachment($upload, $parent_post_id = 0) {
+  public function makeAttachment($upload, $parent_post_id = 0) {
     $type = '';
     if (!empty($upload['type'])) {
         $type = $upload['type'];
@@ -42,7 +42,7 @@ class FunctionsTest extends \MailPoetTest {
     return $this->ids[] = $id;
   }
 
-  function testItCanProcessActions() {
+  public function testItCanProcessActions() {
     $test_value = ['abc', 'def'];
     $test_value2 = new \stdClass;
     $called = false;
@@ -64,7 +64,7 @@ class FunctionsTest extends \MailPoetTest {
     expect($called)->false();
   }
 
-  function testItCanProcessFilters() {
+  public function testItCanProcessFilters() {
     $test_value = ['abc', 'def'];
 
     $called = false;
@@ -86,7 +86,7 @@ class FunctionsTest extends \MailPoetTest {
     expect($called)->false();
   }
 
-  function _after() {
+  public function _after() {
     global $content_width;
     $content_width = $this->_content_width;
   }
diff --git a/tests/integration/WooCommerce/SubscriptionTest.php b/tests/integration/WooCommerce/SubscriptionTest.php
index 73cf0458b4..2400838c68 100644
--- a/tests/integration/WooCommerce/SubscriptionTest.php
+++ b/tests/integration/WooCommerce/SubscriptionTest.php
@@ -28,7 +28,7 @@ class SubscriptionTest extends \MailPoetTest {
   /** @var Subscriber */
   private $subscriber;
 
-  function _before() {
+  public function _before() {
     $this->order_id = 123; // dummy
     $this->subscription = ContainerWrapper::getInstance()->get(Subscription::class);
     $this->settings = SettingsController::getInstance();
@@ -44,7 +44,7 @@ class SubscriptionTest extends \MailPoetTest {
     $this->original_settings = $this->settings->get('woocommerce');
   }
 
-  function testItDisplaysACheckedCheckboxIfCurrentUserIsSubscribed() {
+  public function testItDisplaysACheckedCheckboxIfCurrentUserIsSubscribed() {
     WP::synchronizeUsers();
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
@@ -56,7 +56,7 @@ class SubscriptionTest extends \MailPoetTest {
     expect($this->getRenderedOptinField())->contains('checked');
   }
 
-  function testItDisplaysAnUncheckedCheckboxIfCurrentUserIsNotSubscribed() {
+  public function testItDisplaysAnUncheckedCheckboxIfCurrentUserIsNotSubscribed() {
     WP::synchronizeUsers();
     $wp_users = get_users();
     wp_set_current_user($wp_users[0]->ID);
@@ -68,18 +68,18 @@ class SubscriptionTest extends \MailPoetTest {
     expect($this->getRenderedOptinField())->notContains('checked');
   }
 
-  function testItDisplaysAnUncheckedCheckboxIfCurrentUserIsNotLoggedIn() {
+  public function testItDisplaysAnUncheckedCheckboxIfCurrentUserIsNotLoggedIn() {
     wp_set_current_user(0);
     expect($this->getRenderedOptinField())->notContains('checked');
   }
 
-  function testItDisplaysCheckboxOptinMessageFromSettings() {
+  public function testItDisplaysCheckboxOptinMessageFromSettings() {
     $new_message = 'This is a test message.';
     $this->settings->set(Subscription::OPTIN_MESSAGE_SETTING_NAME, $new_message);
     expect($this->getRenderedOptinField())->contains($new_message);
   }
 
-  function testItsTemplateCanBeOverriddenByAHook() {
+  public function testItsTemplateCanBeOverriddenByAHook() {
     $new_template = 'This is a new template';
     add_filter(
       'mailpoet_woocommerce_checkout_optin_template',
@@ -94,13 +94,13 @@ class SubscriptionTest extends \MailPoetTest {
     expect($result)->contains(Subscription::CHECKOUT_OPTIN_INPUT_NAME);
   }
 
-  function testItDoesNotTryToSubscribeIfThereIsNoEmailInOrderData() {
+  public function testItDoesNotTryToSubscribeIfThereIsNoEmailInOrderData() {
     $data = [];
     $subscribed = $this->subscription->subscribeOnCheckout($this->order_id, $data);
     expect($subscribed)->equals(null);
   }
 
-  function testItDoesNotTryToSubscribeIfSubscriberWithTheEmailWasNotSynced() {
+  public function testItDoesNotTryToSubscribeIfSubscriberWithTheEmailWasNotSynced() {
     // non-existent
     $data['billing_email'] = 'non-existent-subscriber@example.com';
     $subscribed = $this->subscription->subscribeOnCheckout($this->order_id, $data);
@@ -113,7 +113,7 @@ class SubscriptionTest extends \MailPoetTest {
     expect($subscribed)->equals(null);
   }
 
-  function testItUnsubscribesIfCheckoutOptinIsDisabled() {
+  public function testItUnsubscribesIfCheckoutOptinIsDisabled() {
     SubscriberSegment::subscribeToSegments(
       $this->subscriber,
       [$this->wc_segment->id]
@@ -130,7 +130,7 @@ class SubscriptionTest extends \MailPoetTest {
     expect($subscribed_segments)->count(0);
   }
 
-  function testItUnsubscribesIfCheckboxIsNotChecked() {
+  public function testItUnsubscribesIfCheckboxIsNotChecked() {
     SubscriberSegment::subscribeToSegments(
       $this->subscriber,
       [$this->wc_segment->id]
@@ -150,7 +150,7 @@ class SubscriptionTest extends \MailPoetTest {
     expect($subscriber->status)->equals(Subscriber::STATUS_UNSUBSCRIBED);
   }
 
-  function testItSubscribesIfCheckboxIsChecked() {
+  public function testItSubscribesIfCheckboxIsChecked() {
     $this->subscriber->status = Subscriber::STATUS_UNSUBSCRIBED;
     $this->subscriber->save();
 
@@ -182,7 +182,7 @@ class SubscriptionTest extends \MailPoetTest {
     return $result;
   }
 
-  function _after() {
+  public function _after() {
     ORM::raw_execute('TRUNCATE ' . Subscriber::$_table);
     ORM::raw_execute('TRUNCATE ' . SubscriberSegment::$_table);
     // restore settings
diff --git a/tests/integration/WooCommerce/TransactionalEmails/RendererTest.php b/tests/integration/WooCommerce/TransactionalEmails/RendererTest.php
index 248faa14d3..5983d72342 100644
--- a/tests/integration/WooCommerce/TransactionalEmails/RendererTest.php
+++ b/tests/integration/WooCommerce/TransactionalEmails/RendererTest.php
@@ -13,7 +13,7 @@ class RendererTest extends \MailPoetTest {
   /** @var Newsletter */
   private $newsletter;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->newsletter = Stub::make(Newsletter::class, [
       'asArray' => function() {
@@ -35,7 +35,7 @@ class RendererTest extends \MailPoetTest {
     ]);
   }
 
-  function testGetHTMLBeforeContent() {
+  public function testGetHTMLBeforeContent() {
     $renderer = new Renderer(new csstidy);
     $newsletter_renderer = new NewsletterRenderer($this->newsletter, true);
     $newsletter_renderer->preprocessor = new Preprocessor(
@@ -58,7 +58,7 @@ class RendererTest extends \MailPoetTest {
     expect($html)->notContains('Some text after content');
   }
 
-  function testGetHTMLAfterContent() {
+  public function testGetHTMLAfterContent() {
     $renderer = new Renderer(new csstidy);
     $newsletter_renderer = new NewsletterRenderer($this->newsletter, true);
     $newsletter_renderer->preprocessor = new Preprocessor(
@@ -81,7 +81,7 @@ class RendererTest extends \MailPoetTest {
     expect($html)->contains('Some text after content');
   }
 
-  function testPrefixCss() {
+  public function testPrefixCss() {
     $renderer = new Renderer(new csstidy);
     $css = $renderer->prefixCss('
       #some_id {color: black}
diff --git a/tests/integration/WooCommerce/TransactionalEmailsTest.php b/tests/integration/WooCommerce/TransactionalEmailsTest.php
index bc60077235..a44f854cb0 100644
--- a/tests/integration/WooCommerce/TransactionalEmailsTest.php
+++ b/tests/integration/WooCommerce/TransactionalEmailsTest.php
@@ -31,7 +31,7 @@ class TransactionalEmailsTest extends \MailPoetTest {
   /** @var NewslettersRepository */
   private $newsletters_repository;
 
-  function _before() {
+  public function _before() {
     $this->wp = new WPFunctions();
     $this->settings = SettingsController::getInstance();
     $this->original_wc_settings = $this->settings->get('woocommerce');
@@ -46,7 +46,7 @@ class TransactionalEmailsTest extends \MailPoetTest {
     );
   }
 
-  function testInitCreatesTransactionalEmailAndSavesItsId() {
+  public function testInitCreatesTransactionalEmailAndSavesItsId() {
     $this->transactional_emails->init();
     $email = $this->newsletters_repository->findOneBy(['type' => Newsletter::TYPE_WC_TRANSACTIONAL_EMAIL]);
     $id = $this->settings->get(TransactionalEmails::SETTING_EMAIL_ID, null);
@@ -55,14 +55,14 @@ class TransactionalEmailsTest extends \MailPoetTest {
     expect($email->getId())->equals($id);
   }
 
-  function testInitDoesntCreateTransactionalEmailIfSettingAlreadySet() {
+  public function testInitDoesntCreateTransactionalEmailIfSettingAlreadySet() {
     $this->settings->set(TransactionalEmails::SETTING_EMAIL_ID, 1);
     $this->transactional_emails->init();
     $email = $this->newsletters_repository->findOneBy(['type' => Newsletter::TYPE_WC_TRANSACTIONAL_EMAIL]);
     expect($email)->equals(null);
   }
 
-  function testInitUsesImageFromWCSettings() {
+  public function testInitUsesImageFromWCSettings() {
     $wp = Stub::make(new WPFunctions, ['getOption' => function($name) {
       if ($name == 'woocommerce_email_header_image') {
         return 'my-awesome-image-url';
@@ -84,7 +84,7 @@ class TransactionalEmailsTest extends \MailPoetTest {
     expect(json_encode($email->getBody()))->contains('my-awesome-image-url');
   }
 
-  function testItSynchronizesEmailSettingsToWooCommerce() {
+  public function testItSynchronizesEmailSettingsToWooCommerce() {
     $newsletter = new NewsletterEntity;
     $newsletter->setType(Newsletter::TYPE_WC_TRANSACTIONAL_EMAIL);
     $newsletter->setSubject('WooCommerce Transactional Email');
@@ -170,7 +170,7 @@ class TransactionalEmailsTest extends \MailPoetTest {
     expect($wp->getOption('woocommerce_email_text_color'))->equals('#111111');
   }
 
-  function testUseTemplateForWCEmails() {
+  public function testUseTemplateForWCEmails() {
     $added_actions = [];
     $removed_actions = [];
     $newsletter = new NewsletterEntity;
@@ -240,7 +240,7 @@ class TransactionalEmailsTest extends \MailPoetTest {
     expect($added_actions['woocommerce_email_styles']('some css'))->equals('prefixed some css');
   }
 
-  function _after() {
+  public function _after() {
     $this->entity_manager
       ->createQueryBuilder()
       ->delete()
diff --git a/tests/integration/_bootstrap.php b/tests/integration/_bootstrap.php
index 0f91f8b46d..fa4e54eb1f 100644
--- a/tests/integration/_bootstrap.php
+++ b/tests/integration/_bootstrap.php
@@ -158,7 +158,7 @@ abstract class MailPoetTest extends \Codeception\TestCase\Test {
   /** @var EntityManager */
   protected $entity_manager;
 
-  function setUp() {
+  public function setUp() {
     $this->di_container = ContainerWrapper::getInstance(WP_DEBUG);
     $this->connection = $this->di_container->get(Connection::class);
     $this->entity_manager = $this->di_container->get(EntityManager::class);
@@ -167,7 +167,7 @@ abstract class MailPoetTest extends \Codeception\TestCase\Test {
     parent::setUp();
   }
 
-  function tearDown() {
+  public function tearDown() {
     $this->entity_manager->clear();
     parent::tearDown();
   }
@@ -211,20 +211,20 @@ function asCallable($fn) {
 if (!class_exists(WC_Session::class)) {
   // phpcs:ignore
   class WC_Session {
-    function __unset($name) {
+    public function __unset($name) {
     }
   }
 }
 
 if (!function_exists('WC')) {
   class WC_Mailer { // phpcs:ignore
-    function email_header() { // phpcs:ignore
+    public function email_header() { // phpcs:ignore
     }
-    function email_footer() { // phpcs:ignore
+    public function email_footer() { // phpcs:ignore
     }
   }
   class WooCommerce { // phpcs:ignore
-    function mailer() {
+    public function mailer() {
       return new WC_Mailer;
     }
   }
@@ -232,7 +232,7 @@ if (!function_exists('WC')) {
     return new WooCommerce;
   }
   class WC_Order_Item_Product { // phpcs:ignore
-    function get_product_id() { // phpcs:ignore
+    public function get_product_id() { // phpcs:ignore
     }
   }
 }
diff --git a/tests/integration/_fixtures.php b/tests/integration/_fixtures.php
index 030122102e..163ae6176f 100644
--- a/tests/integration/_fixtures.php
+++ b/tests/integration/_fixtures.php
@@ -173,7 +173,7 @@ Fixtures::add(
 class DynamicSegmentFilter { // phpcs:ignore PSR1.Classes.ClassDeclaration, Squiz.Classes.ClassFileName
   protected $ids;
 
-  function __construct($ids) {
+  public function __construct($ids) {
     $this->ids = $ids;
   }
 
diff --git a/tests/unit/API/JSON/ErrorResponseTest.php b/tests/unit/API/JSON/ErrorResponseTest.php
index 90f12e3db5..c29f5cdab5 100644
--- a/tests/unit/API/JSON/ErrorResponseTest.php
+++ b/tests/unit/API/JSON/ErrorResponseTest.php
@@ -7,7 +7,7 @@ use MailPoet\API\JSON\ErrorResponse;
 use MailPoet\WP\Functions as WPFunctions;
 
 class ErrorResponseTest extends \MailPoetUnitTest {
-  function testItSanitizesSqlErrorsWhenReturningResponse() {
+  public function testItSanitizesSqlErrorsWhenReturningResponse() {
     WPFunctions::set(Stub::make(new WPFunctions, [
       '__' => function ($value) {
         return $value;
@@ -39,7 +39,7 @@ class ErrorResponseTest extends \MailPoetUnitTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
\ No newline at end of file
diff --git a/tests/unit/Cron/CronTriggerTest.php b/tests/unit/Cron/CronTriggerTest.php
index eefdb10cce..caee3cf2aa 100644
--- a/tests/unit/Cron/CronTriggerTest.php
+++ b/tests/unit/Cron/CronTriggerTest.php
@@ -9,7 +9,7 @@ use MailPoet\Cron\Triggers\WordPress;
 use MailPoet\Settings\SettingsController;
 
 class CronTriggerTest extends \MailPoetUnitTest {
-  function testItDefinesConstants() {
+  public function testItDefinesConstants() {
     expect(CronTrigger::METHOD_LINUX_CRON)->same('Linux Cron');
     expect(CronTrigger::METHOD_MAILPOET)->same('MailPoet');
     expect(CronTrigger::METHOD_WORDPRESS)->same('WordPress');
@@ -23,7 +23,7 @@ class CronTriggerTest extends \MailPoetUnitTest {
     expect(CronTrigger::SETTING_NAME)->equals('cron_trigger');
   }
 
-  function testItCanInitializeCronTriggerMethod() {
+  public function testItCanInitializeCronTriggerMethod() {
     $settings_mock = Stub::makeEmpty(SettingsController::class, [
       'get' => CronTrigger::METHOD_WORDPRESS,
     ]);
@@ -31,7 +31,7 @@ class CronTriggerTest extends \MailPoetUnitTest {
     expect($cron_trigger->init())->true();
   }
 
-  function testItReturnsFalseWhenItCantInitializeCronTriggerMethod() {
+  public function testItReturnsFalseWhenItCantInitializeCronTriggerMethod() {
     $settings_mock = Stub::makeEmpty(SettingsController::class, [
       'get' => 'unknown-method',
     ]);
@@ -39,7 +39,7 @@ class CronTriggerTest extends \MailPoetUnitTest {
     expect($cron_trigger->init())->false();
   }
 
-  function testItIgnoresExceptionsThrownFromCronTriggerMethods() {
+  public function testItIgnoresExceptionsThrownFromCronTriggerMethods() {
     $settings_mock = Stub::makeEmpty(SettingsController::class, [
       'get' => CronTrigger::METHOD_MAILPOET,
     ]);
diff --git a/tests/unit/Cron/Workers/StatsNotifications/SchedulerTest.php b/tests/unit/Cron/Workers/StatsNotifications/SchedulerTest.php
index 8ed514cfed..2cf5bc4044 100644
--- a/tests/unit/Cron/Workers/StatsNotifications/SchedulerTest.php
+++ b/tests/unit/Cron/Workers/StatsNotifications/SchedulerTest.php
@@ -22,7 +22,7 @@ class SchedulerTest extends \MailPoetUnitTest {
   /** @var StatsNotificationsRepository|\PHPUnit_Framework_MockObject_MockObject */
   private $repository;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = $this->createMock(SettingsController::class);
     $this->entityManager = $this->createMock(EntityManager::class);
@@ -35,7 +35,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     );
   }
 
-  function testShouldSchedule() {
+  public function testShouldSchedule() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -75,7 +75,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldScheduleForNotificationHistory() {
+  public function testShouldScheduleForNotificationHistory() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -115,7 +115,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfTrackingIsDisabled() {
+  public function testShouldNotScheduleIfTrackingIsDisabled() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -135,7 +135,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfDisabled() {
+  public function testShouldNotScheduleIfDisabled() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -155,7 +155,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfSettingsMissing() {
+  public function testShouldNotScheduleIfSettingsMissing() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -176,7 +176,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfEmailIsMissing() {
+  public function testShouldNotScheduleIfEmailIsMissing() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -196,7 +196,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfEmailIsEmpty() {
+  public function testShouldNotScheduleIfEmailIsEmpty() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -215,7 +215,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfAlreadyScheduled() {
+  public function testShouldNotScheduleIfAlreadyScheduled() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
@@ -240,7 +240,7 @@ class SchedulerTest extends \MailPoetUnitTest {
     $this->stats_notifications->schedule($newsletter);
   }
 
-  function testShouldNotScheduleIfInvalidType() {
+  public function testShouldNotScheduleIfInvalidType() {
     $this->settings
       ->method('get')
       ->will($this->returnValueMap([
diff --git a/tests/unit/CustomFields/ApiDataSanitizerTest.php b/tests/unit/CustomFields/ApiDataSanitizerTest.php
index f0eb35bbc8..ef41c14d81 100644
--- a/tests/unit/CustomFields/ApiDataSanitizerTest.php
+++ b/tests/unit/CustomFields/ApiDataSanitizerTest.php
@@ -9,107 +9,107 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
   /** @var ApiDataSanitizer */
   private $sanitizer;
 
-  function _before() {
+  public function _before() {
     $this->sanitizer = new ApiDataSanitizer();
   }
 
-  function testItThrowsIfNameIsMissing() {
+  public function testItThrowsIfNameIsMissing() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['type' => 'text']);
   }
 
-  function testItThrowsIfNameIsEmpty() {
+  public function testItThrowsIfNameIsEmpty() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => '', 'type' => 'text']);
   }
 
-  function testItThrowsIfNameIsWrongType() {
+  public function testItThrowsIfNameIsWrongType() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => ['x'], 'type' => 'text']);
   }
 
-  function testItThrowsIfTypeIsMissing() {
+  public function testItThrowsIfTypeIsMissing() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name']);
   }
 
-  function testItThrowsIfTypeIsEmpty() {
+  public function testItThrowsIfTypeIsEmpty() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name', 'type' => '']);
   }
 
-  function testItThrowsIfTypeIsWrongType() {
+  public function testItThrowsIfTypeIsWrongType() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name', 'type' => ['y']]);
   }
 
-  function testItThrowsIfTypeIsInvalid() {
+  public function testItThrowsIfTypeIsInvalid() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'Invalid Type']);
   }
 
-  function testItThrowsIfParamsIsInvalidType() {
+  public function testItThrowsIfParamsIsInvalidType() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => 'xyz']);
   }
 
-  function testItReturnsArray() {
+  public function testItReturnsArray() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text']);
     expect($result)->internalType('array');
   }
 
-  function testItReturnsName() {
+  public function testItReturnsName() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text']);
     expect($result)->hasKey('name');
     expect($result['name'])->same('Name');
   }
 
-  function testItReturnsType() {
+  public function testItReturnsType() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'Text']);
     expect($result)->hasKey('type');
     expect($result['type'])->same('text');
   }
 
-  function testItIgnoresUnknownProperties() {
+  public function testItIgnoresUnknownProperties() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'unknown' => 'Unknown property']);
     expect($result)->hasntKey('unknown');
   }
 
-  function testItReturnsParamsIfPassed() {
+  public function testItReturnsParamsIfPassed() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['required' => '1']]);
     expect($result)->hasKey('params');
   }
 
-  function testItReturnsCorrectRequiredForm() {
+  public function testItReturnsCorrectRequiredForm() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['required' => true]]);
     expect($result['params']['required'])->same('1');
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['required' => false]]);
     expect($result['params']['required'])->same('');
   }
 
-  function testItIgnoresUnknownParams() {
+  public function testItIgnoresUnknownParams() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['unknown' => 'Unknown property']]);
     expect($result)->hasKey('params');
     expect($result['params'])->hasntKey('unknown');
   }
 
-  function testItFillsLabel() {
+  public function testItFillsLabel() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text']);
     expect($result['params'])->hasKey('label');
     expect($result['params']['label'])->same('Name');
   }
 
-  function testItThrowsForInvalidValidate() {
+  public function testItThrowsForInvalidValidate() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['validate' => 'unknown']]);
   }
 
-  function testItReturnsSanitizedValidate() {
+  public function testItReturnsSanitizedValidate() {
     $result = $this->sanitizer->sanitize(['name' => 'Name', 'type' => 'text', 'params' => ['validate' => 'alphanuM']]);
     expect($result['params']['validate'])->same('alphanum');
   }
 
-  function testItThrowsIfNoValuesInRadio() {
+  public function testItThrowsIfNoValuesInRadio() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -117,7 +117,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItReturnsSanitizedValuesForRadio() {
+  public function testItReturnsSanitizedValuesForRadio() {
     $result = $this->sanitizer->sanitize([
       'name' => 'Name',
       'type' => 'radio',
@@ -141,7 +141,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     expect($values[1])->same(['value' => 'value 2', 'is_checked' => '1']);
   }
 
-  function testItThrowsIfNoValuesInCheckbox() {
+  public function testItThrowsIfNoValuesInCheckbox() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -149,7 +149,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItThrowsIfMoreValuesInCheckbox() {
+  public function testItThrowsIfMoreValuesInCheckbox() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -167,7 +167,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItThrowsIfNameValueMissingInCheckbox() {
+  public function testItThrowsIfNameValueMissingInCheckbox() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -182,7 +182,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItSanitizeCheckbox() {
+  public function testItSanitizeCheckbox() {
     $result = $this->sanitizer->sanitize([
       'name' => 'Name',
       'type' => 'checkbox',
@@ -201,7 +201,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     expect($values[0])->same(['value' => 'value 1', 'is_checked' => '1']);
   }
 
-  function testDateThrowsIfNoDateFormat() {
+  public function testDateThrowsIfNoDateFormat() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -210,7 +210,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testDateThrowsIfInvalidDateFormat() {
+  public function testDateThrowsIfInvalidDateFormat() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -219,7 +219,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testDateThrowsIfInvalidDateType() {
+  public function testDateThrowsIfInvalidDateType() {
     $this->expectException(InvalidArgumentException::class);
     $this->sanitizer->sanitize([
       'name' => 'Name',
@@ -228,7 +228,7 @@ class ApiDataSanitizerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testSanitizeDate() {
+  public function testSanitizeDate() {
     $result = $this->sanitizer->sanitize([
       'name' => 'Name',
       'type' => 'date',
diff --git a/tests/unit/DI/ContainerWrapperTest.php b/tests/unit/DI/ContainerWrapperTest.php
index f18ae2fa95..d836294ae9 100644
--- a/tests/unit/DI/ContainerWrapperTest.php
+++ b/tests/unit/DI/ContainerWrapperTest.php
@@ -10,7 +10,7 @@ use MailPoetVendor\Symfony\Component\DependencyInjection\ContainerBuilder;
 use MailPoetVendor\Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
 
 class ContainerWrapperTest extends \MailPoetUnitTest {
-  function testItCanConstruct() {
+  public function testItCanConstruct() {
     $instance = new ContainerWrapper(new ContainerBuilder());
     expect($instance)->isInstanceOf(ContainerWrapper::class);
     expect($instance)->isInstanceOf(ContainerInterface::class);
@@ -20,7 +20,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
     expect($instance)->isInstanceOf(ContainerInterface::class);
   }
 
-  function testItProvidesPremiumContainerIfAvailable() {
+  public function testItProvidesPremiumContainerIfAvailable() {
     $instance = new ContainerWrapper(new ContainerBuilder());
     expect($instance->getPremiumContainer())->null();
 
@@ -28,7 +28,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
     expect($instance->getPremiumContainer())->isInstanceOf(ContainerBuilder::class);
   }
 
-  function testItProvidesFreePluginServices() {
+  public function testItProvidesFreePluginServices() {
     $free_container_stub = Stub::make(Container::class, [
       'get' => function () {
           return 'service';
@@ -39,7 +39,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
     expect($service)->equals('service');
   }
 
-  function testItThrowsFreePluginServices() {
+  public function testItThrowsFreePluginServices() {
     $free_container_stub = Stub::make(Container::class, [
       'get' => function ($id) {
         throw new ServiceNotFoundException($id);
@@ -55,7 +55,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
     expect($exception)->isInstanceOf(ServiceNotFoundException::class);
   }
 
-  function testItReturnServiceFromPremium() {
+  public function testItReturnServiceFromPremium() {
     $free_container_stub = Stub::make(Container::class, [
       'get' => function ($id) {
         throw new ServiceNotFoundException($id);
@@ -70,7 +70,7 @@ class ContainerWrapperTest extends \MailPoetUnitTest {
     expect($instance->get('service'))->equals('service_1');
   }
 
-  function testItThrowsIfServiceNotFoundInBothContainers() {
+  public function testItThrowsIfServiceNotFoundInBothContainers() {
     $container_stub = Stub::make(Container::class, [
       'get' => function ($id) {
         throw new ServiceNotFoundException($id);
diff --git a/tests/unit/DynamicSegments/RequirementsCheckerTest.php b/tests/unit/DynamicSegments/RequirementsCheckerTest.php
index b575504b5c..4495ceac87 100644
--- a/tests/unit/DynamicSegments/RequirementsCheckerTest.php
+++ b/tests/unit/DynamicSegments/RequirementsCheckerTest.php
@@ -15,7 +15,7 @@ class RequirementsCheckerTest extends \MailPoetUnitTest {
   /** @var RequirementsChecker */
   private $requirements_checker;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     if (!defined('MP_SEGMENTS_TABLE')) define('MP_SEGMENTS_TABLE', '');
     $this->woocommerce_helper = $this
@@ -25,21 +25,21 @@ class RequirementsCheckerTest extends \MailPoetUnitTest {
     $this->requirements_checker = new RequirementsChecker($this->woocommerce_helper);
   }
 
-  function testShouldntBlockSegmentIfWooCommerceIsActive() {
+  public function testShouldntBlockSegmentIfWooCommerceIsActive() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(true);
     $segment = DynamicSegment::create();
     $segment->setFilters([new WooCommerceCategory(1)]);
     expect($this->requirements_checker->shouldSkipSegment($segment))->false();
   }
 
-  function testShouldBlockWooCommerceSegmentIfWooCommerceIsInactive() {
+  public function testShouldBlockWooCommerceSegmentIfWooCommerceIsInactive() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(false);
     $segment = DynamicSegment::create();
     $segment->setFilters([new WooCommerceCategory(1)]);
     expect($this->requirements_checker->shouldSkipSegment($segment))->true();
   }
 
-  function testShouldntBlockNonWooCommerceSegmentIfWooCommerceIsInactive() {
+  public function testShouldntBlockNonWooCommerceSegmentIfWooCommerceIsInactive() {
     $this->woocommerce_helper->method('isWooCommerceActive')->willReturn(false);
     $segment = DynamicSegment::create();
     $segment->setFilters([new EmailAction(EmailAction::ACTION_OPENED, 2)]);
diff --git a/tests/unit/Features/FeaturesControllerTest.php b/tests/unit/Features/FeaturesControllerTest.php
index a83a0f3500..3264142949 100644
--- a/tests/unit/Features/FeaturesControllerTest.php
+++ b/tests/unit/Features/FeaturesControllerTest.php
@@ -8,7 +8,7 @@ use MailPoet\Features\FeaturesController;
 
 class FeaturesControllerTest extends \MailPoetUnitTest {
 
-  function testItWorksWithDefaults() {
+  public function testItWorksWithDefaults() {
     $repository = $this->makeEmpty(
       FeatureFlagsRepository::class,
       [
@@ -34,7 +34,7 @@ class FeaturesControllerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItWorksWithDatabaseValues() {
+  public function testItWorksWithDatabaseValues() {
     $repository = $this->makeEmpty(
       FeatureFlagsRepository::class,
       [
@@ -54,7 +54,7 @@ class FeaturesControllerTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function testItDoesNotReturnUnknownFlag() {
+  public function testItDoesNotReturnUnknownFlag() {
     $repository = $this->makeEmpty(
       FeatureFlagsRepository::class,
       [
diff --git a/tests/unit/Form/Block/DateTest.php b/tests/unit/Form/Block/DateTest.php
index 7c5b7aa637..b926c50733 100644
--- a/tests/unit/Form/Block/DateTest.php
+++ b/tests/unit/Form/Block/DateTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Form\Block;
 use MailPoet\Form\Block\Date;
 
 class DateTest extends \MailPoetUnitTest {
-  function testItCanConvertDateMonthYearFormatToDatetime() {
+  public function testItCanConvertDateMonthYearFormatToDatetime() {
     $date = [
       'MM/DD/YYYY' => '05/10/2016',
       'DD/MM/YYYY' => '10/05/2016',
@@ -18,7 +18,7 @@ class DateTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItCanConvertMonthYearFormatToDatetime() {
+  public function testItCanConvertMonthYearFormatToDatetime() {
     $date = [
       'MM/YYYY' => '05/2016',
       'YYYY/MM' => '2016/05',
@@ -29,23 +29,23 @@ class DateTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItCanConvertMonthToDatetime() {
+  public function testItCanConvertMonthToDatetime() {
     $current_year = date('Y');
     expect(Date::convertDateToDatetime('05', 'MM'))
       ->equals(sprintf('%s-05-01 00:00:00', $current_year));
   }
 
-  function testItCanConvertYearToDatetime() {
+  public function testItCanConvertYearToDatetime() {
     expect(Date::convertDateToDatetime('2016', 'YYYY'))
       ->equals('2016-01-01 00:00:00');
   }
 
-  function testItCanConvertDatetimeToDatetime() {
+  public function testItCanConvertDatetimeToDatetime() {
     expect(Date::convertDateToDatetime('2016-05-10 00:00:00', 'datetime'))
       ->equals('2016-05-10 00:00:00');
   }
 
-  function testItCanClearDate() {
+  public function testItCanClearDate() {
     expect(Date::convertDateToDatetime('0/10/5', 'YYYY/MM/DD'))
       ->equals(date('Y') . '-10-05 00:00:00');
     expect(Date::convertDateToDatetime('0/0/5', 'YYYY/MM/DD'))
diff --git a/tests/unit/Form/Util/FieldNameObfuscatorTest.php b/tests/unit/Form/Util/FieldNameObfuscatorTest.php
index edf4748070..4f79d500b7 100644
--- a/tests/unit/Form/Util/FieldNameObfuscatorTest.php
+++ b/tests/unit/Form/Util/FieldNameObfuscatorTest.php
@@ -6,7 +6,7 @@ use Codeception\Stub;
 use MailPoet\WP\Functions as WPFunctions;
 
 class FieldNameObfuscatorTest extends \MailPoetUnitTest {
-  function _before() {
+  public function _before() {
     parent::_before();
     WPFunctions::set(
       Stub::make(WPFunctions::class, [
@@ -40,7 +40,7 @@ class FieldNameObfuscatorTest extends \MailPoetUnitTest {
     ]);
   }
 
-  function _after() {
+  public function _after() {
     parent::_after();
     WPFunctions::set(new WPFunctions());
   }
diff --git a/tests/unit/Form/Util/StylesTest.php b/tests/unit/Form/Util/StylesTest.php
index 936adcd481..ad823a8740 100644
--- a/tests/unit/Form/Util/StylesTest.php
+++ b/tests/unit/Form/Util/StylesTest.php
@@ -10,7 +10,7 @@ class StylesTest extends \MailPoetUnitTest {
   /** @var FeaturesController&\PHPUnit_Framework_MockObject_MockObject */
   private $features_controller;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->features_controller = $this->createMock(FeaturesController::class);
     $this->features_controller
@@ -19,12 +19,12 @@ class StylesTest extends \MailPoetUnitTest {
       ->willReturn(false);
   }
 
-  function testItSetsDefaultCSSStyles() {
+  public function testItSetsDefaultCSSStyles() {
     $styles = new Styles($this->features_controller);
     expect($styles->getDefaultStyles())->notEmpty();
   }
 
-  function testItProcessesAndRendersStyles() {
+  public function testItProcessesAndRendersStyles() {
     $stylesheet = '
     /* some comment */
     input[name=first_name]    , input.some_class,     .some_class { color: red  ; background: blue; } .another_style { fonT-siZe: 20px                            }
diff --git a/tests/unit/Logging/LoggerFactoryTest.php b/tests/unit/Logging/LoggerFactoryTest.php
index b2a92d4ad6..814cc5df5f 100644
--- a/tests/unit/Logging/LoggerFactoryTest.php
+++ b/tests/unit/Logging/LoggerFactoryTest.php
@@ -14,7 +14,7 @@ class LoggerFactoryTest extends \MailPoetUnitTest {
   /** @var LoggerFactory */
   private $logger_factory;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->settings = $this->createMock(SettingsController::class);
     $this->logger_factory = new LoggerFactory($this->settings);
diff --git a/tests/unit/Mailer/MailerErrorTest.php b/tests/unit/Mailer/MailerErrorTest.php
index 794a0a138d..896d0d83f1 100644
--- a/tests/unit/Mailer/MailerErrorTest.php
+++ b/tests/unit/Mailer/MailerErrorTest.php
@@ -9,7 +9,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class MailerErrorTest extends \MailPoetUnitTest {
 
-  function _before() {
+  public function _before() {
     WPFunctions::set(Stub::make(new WPFunctions, [
       '__' => function ($value) {
         return $value;
@@ -17,12 +17,12 @@ class MailerErrorTest extends \MailPoetUnitTest {
     ]));
   }
 
-  function testItCanComposeErrorMessageWithoutSubscribers() {
+  public function testItCanComposeErrorMessageWithoutSubscribers() {
     $error = new MailerError(MailerError::OPERATION_SEND, MailerError::LEVEL_HARD, 'Some Message');
     expect($error->getMessageWithFailedSubscribers())->equals('Some Message');
   }
 
-  function testItCanComposeErrorMessageWithOneSubscriber() {
+  public function testItCanComposeErrorMessageWithOneSubscriber() {
     $subscriber_error = new SubscriberError('email@example.com', 'Subscriber message');
     $error = new MailerError(
       MailerError::OPERATION_SEND,
@@ -34,7 +34,7 @@ class MailerErrorTest extends \MailPoetUnitTest {
     expect($error->getMessageWithFailedSubscribers())->equals('Some Message Unprocessed subscriber: (email@example.com: Subscriber message)');
   }
 
-  function testItCanComposeErrorMessageWithMultipleSubscriberErrors() {
+  public function testItCanComposeErrorMessageWithMultipleSubscriberErrors() {
     $subscriber_error_1 = new SubscriberError('email1@example.com', 'Subscriber 1 message');
     $subscriber_error_2 = new SubscriberError('email2@example.com', null);
     $error = new MailerError(
@@ -49,7 +49,7 @@ class MailerErrorTest extends \MailPoetUnitTest {
     );
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/AmazonSESMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/AmazonSESMapperTest.php
index 57ff596b39..fbab88664a 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/AmazonSESMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/AmazonSESMapperTest.php
@@ -14,7 +14,7 @@ class AmazonSESMapperTest extends \MailPoetUnitTest {
   /** @var array */
   private $response_data = [];
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mapper = new AmazonSESMapper();
     $this->response_data = [
@@ -27,7 +27,7 @@ class AmazonSESMapperTest extends \MailPoetUnitTest {
     ];
   }
 
-  function testGetProperError() {
+  public function testGetProperError() {
     $response = $this->buildXmlResponseFromArray($this->response_data, new SimpleXMLElement('<response/>'));
     $error = $this->mapper->getErrorFromResponse($response, 'john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_HARD);
@@ -35,7 +35,7 @@ class AmazonSESMapperTest extends \MailPoetUnitTest {
     expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
   }
 
-  function testGetSoftErrorForRejectedMessage() {
+  public function testGetSoftErrorForRejectedMessage() {
     $this->response_data['Error']['Code'] = 'MessageRejected';
     $response = $this->buildXmlResponseFromArray($this->response_data, new SimpleXMLElement('<response/>'));
     $error = $this->mapper->getErrorFromResponse($response, 'john@rambo.com');
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
index 16e88262e0..58f526aada 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/MailPoetMapperTest.php
@@ -13,13 +13,13 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
   /** @var array */
   private $subscribers;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mapper = new MailPoetMapper();
     $this->subscribers = ['a@example.com', 'c d <b@example.com>'];
   }
 
-  function testCreateBlacklistError() {
+  public function testCreateBlacklistError() {
     $error = $this->mapper->getBlacklistError($this->subscribers[1]);
     expect($error)->isInstanceOf(MailerError::class);
     expect($error->getOperation())->equals(MailerError::OPERATION_SEND);
@@ -28,7 +28,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->contains('MailPoet');
   }
 
-  function testCreateConnectionError() {
+  public function testCreateConnectionError() {
     $error = $this->mapper->getConnectionError('connection error');
     expect($error)->isInstanceOf(MailerError::class);
     expect($error->getOperation())->equals(MailerError::OPERATION_CONNECT);
@@ -36,7 +36,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->equals('connection error');
   }
 
-  function testGetErrorNotArray() {
+  public function testGetErrorNotArray() {
     $api_result = [
       'code' => API::RESPONSE_CODE_NOT_ARRAY,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -50,7 +50,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->equals('JSON input is not an array');
   }
 
-  function testGetErrorBannedAccount() {
+  public function testGetErrorBannedAccount() {
     $api_result = [
       'code' => API::RESPONSE_CODE_CAN_NOT_SEND,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -64,7 +64,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->contains('The MailPoet Sending Service has stopped sending your emails for one of the following reasons');
   }
 
-  function testGetErrorUnauthorizedEmail() {
+  public function testGetErrorUnauthorizedEmail() {
     $api_result = [
       'code' => API::RESPONSE_CODE_CAN_NOT_SEND,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -78,7 +78,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->contains('The MailPoet Sending Service did not send your latest email because the address');
   }
 
-  function testGetErrorPayloadTooBig() {
+  public function testGetErrorPayloadTooBig() {
     $api_result = [
       'code' => API::RESPONSE_CODE_PAYLOAD_TOO_BIG,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -91,7 +91,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->equals('error too big');
   }
 
-  function testGetPayloadError() {
+  public function testGetPayloadError() {
     $api_result = [
       'code' => API::RESPONSE_CODE_PAYLOAD_ERROR,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -104,7 +104,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($error->getMessage())->equals('Error while sending. Api Error');
   }
 
-  function testGetPayloadErrorWithErrorMessage() {
+  public function testGetPayloadErrorWithErrorMessage() {
     $api_result = [
       'code' => API::RESPONSE_CODE_PAYLOAD_ERROR,
       'status' => API::SENDING_STATUS_SEND_ERROR,
@@ -122,7 +122,7 @@ class MailPoetMapperTest extends \MailPoetUnitTest {
     expect($subscriber_errors[1]->getMessage())->equals('subject is missing');
   }
 
-  function testGetPayloadErrorForMalformedMSSResponse() {
+  public function testGetPayloadErrorForMalformedMSSResponse() {
     $api_result = [
       'code' => API::RESPONSE_CODE_PAYLOAD_ERROR,
       'status' => API::SENDING_STATUS_SEND_ERROR,
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/PHPMailMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/PHPMailMapperTest.php
index 09f4b2148f..8b543cb558 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/PHPMailMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/PHPMailMapperTest.php
@@ -12,7 +12,7 @@ class PHPMailMapperTest extends \MailPoetUnitTest {
   /** @var PHPMailMapper*/
   private $mapper;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mapper = new PHPMailMapper();
     WPFunctions::set(Stub::make(new WPFunctions, [
@@ -22,26 +22,26 @@ class PHPMailMapperTest extends \MailPoetUnitTest {
     ]));
   }
 
-  function testGetProperErrorForSubscriber() {
+  public function testGetProperErrorForSubscriber() {
     $error = $this->mapper->getErrorForSubscriber('john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_HARD);
     expect($error->getMessage())->equals('PHPMail has returned an unknown error.');
     expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
   }
 
-  function testGetProperErrorFromException() {
+  public function testGetProperErrorFromException() {
     $error = $this->mapper->getErrorFromException(new \Exception('Some message'), 'john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_HARD);
     expect($error->getMessage())->equals('Some message');
     expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
   }
 
-  function testGetSoftErrorFromExceptionForInvalidEmail() {
+  public function testGetSoftErrorFromExceptionForInvalidEmail() {
     $error = $this->mapper->getErrorFromException(new \Exception('Invalid address. (Add ...'), 'john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_SOFT);
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
index 89a78ea81f..17a40de603 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/SMTPMapperTest.php
@@ -14,7 +14,7 @@ class SMTPMapperTest extends \MailPoetUnitTest {
   /** @var SMTPMapper */
   private $mapper;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mapper = new SMTPMapper();
     WPFunctions::set(Stub::make(new WPFunctions, [
@@ -24,7 +24,7 @@ class SMTPMapperTest extends \MailPoetUnitTest {
     ]));
   }
 
-  function testItCanProcessExceptionMessage() {
+  public function testItCanProcessExceptionMessage() {
     $message = 'Connection could not be established with host localhost [Connection refused #111]' . PHP_EOL
       . 'Log data:' . PHP_EOL
       . '++ Starting Swift_SmtpTransport' . PHP_EOL
@@ -36,13 +36,13 @@ class SMTPMapperTest extends \MailPoetUnitTest {
     expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
   }
 
-  function testItCreatesSoftErrorForInvalidEmail() {
+  public function testItCreatesSoftErrorForInvalidEmail() {
     $message = 'Invalid email';
     $error = $this->mapper->getErrorFromException(new Swift_RfcComplianceException($message), 'john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_SOFT);
   }
 
-  function testItCanProcessLogMessageWhenOneExists() {
+  public function testItCanProcessLogMessageWhenOneExists() {
     $log = '++ Swift_SmtpTransport started' . PHP_EOL
       . '>> MAIL FROM:<moi@mrcasual.com>' . PHP_EOL
       . '<< 250 OK' . PHP_EOL
@@ -58,14 +58,14 @@ class SMTPMapperTest extends \MailPoetUnitTest {
     expect($error->getSubscriberErrors()[0]->getEmail('moi@mrcasual.com'));
   }
 
-  function testItReturnsGenericMessageWhenLogMessageDoesNotExist() {
+  public function testItReturnsGenericMessageWhenLogMessageDoesNotExist() {
     $error = $this->mapper->getErrorFromLog(null, 'test@example.com');
     expect($error->getMessage())
       ->equals(Mailer::METHOD_SMTP . ' has returned an unknown error.');
     expect($error->getSubscriberErrors()[0]->getEmail('moi@mrcasual.com'));
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/unit/Mailer/Methods/ErrorMappers/SendGridMapperTest.php b/tests/unit/Mailer/Methods/ErrorMappers/SendGridMapperTest.php
index 39fec83ce1..40e8ee130d 100644
--- a/tests/unit/Mailer/Methods/ErrorMappers/SendGridMapperTest.php
+++ b/tests/unit/Mailer/Methods/ErrorMappers/SendGridMapperTest.php
@@ -13,7 +13,7 @@ class SendGridMapperTest extends \MailPoetUnitTest {
   /** @var array */
   private $response = [];
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->mapper = new SendGridMapper();
     $this->response = [
@@ -23,14 +23,14 @@ class SendGridMapperTest extends \MailPoetUnitTest {
     ];
   }
 
-  function testGetProperError() {
+  public function testGetProperError() {
     $error = $this->mapper->getErrorFromResponse($this->response, 'john@rambo.com');
     expect($error->getLevel())->equals(MailerError::LEVEL_HARD);
     expect($error->getMessage())->equals('Some message');
     expect($error->getSubscriberErrors()[0]->getEmail())->equals('john@rambo.com');
   }
 
-  function testGetSoftErrorForInvalidEmail() {
+  public function testGetSoftErrorForInvalidEmail() {
     $this->response['errors'][0] = 'Invalid email address ,,@';
     $error = $this->mapper->getErrorFromResponse($this->response, ',,@');
     expect($error->getLevel())->equals(MailerError::LEVEL_SOFT);
diff --git a/tests/unit/Newsletter/Editor/StructureTransformerTest.php b/tests/unit/Newsletter/Editor/StructureTransformerTest.php
index fb6864b8f2..a078ad398c 100644
--- a/tests/unit/Newsletter/Editor/StructureTransformerTest.php
+++ b/tests/unit/Newsletter/Editor/StructureTransformerTest.php
@@ -8,12 +8,12 @@ class StructureTransformerTest extends \MailPoetUnitTest {
   /** @var StructureTransformer */
   private $transformer;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->transformer = new StructureTransformer();
   }
 
-  function testItExtractsImagesAsImageBlocks() {
+  public function testItExtractsImagesAsImageBlocks() {
     $html = '<p><i>italic</i><em>previous text<a href="#mylink"><img src="#myimage" /></a>next text</em><b>bolded</b></p>';
 
     $blocks = $this->transformer->transform($html, false);
diff --git a/tests/unit/Newsletter/Renderer/Blocks/ButtonTest.php b/tests/unit/Newsletter/Renderer/Blocks/ButtonTest.php
index d5cb9b52cd..0f662f439b 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/ButtonTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/ButtonTest.php
@@ -26,7 +26,7 @@ class ButtonTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Button::render($this->block, 200);
     $expected_result = '
       <tr>
diff --git a/tests/unit/Newsletter/Renderer/Blocks/DividerTest.php b/tests/unit/Newsletter/Renderer/Blocks/DividerTest.php
index c11f4a3ef5..9e18e1c615 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/DividerTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/DividerTest.php
@@ -17,7 +17,7 @@ class DividerTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Divider::render($this->block);
     $expected_result = '
       <tr>
diff --git a/tests/unit/Newsletter/Renderer/Blocks/FooterTest.php b/tests/unit/Newsletter/Renderer/Blocks/FooterTest.php
index 9734275b4c..158a6c4e3a 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/FooterTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/FooterTest.php
@@ -24,7 +24,7 @@ class FooterTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Footer::render($this->block);
     $expected_result = '
       <tr>
@@ -35,7 +35,7 @@ class FooterTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItRendersWithBackgroundColor() {
+  public function testItRendersWithBackgroundColor() {
     $this->block['styles']['block']['backgroundColor'] = '#f0f0f0';
     $output = Footer::render($this->block);
     $expected_result = '
@@ -47,7 +47,7 @@ class FooterTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItPrefersInlinedCssForLinks() {
+  public function testItPrefersInlinedCssForLinks() {
     $this->block['text'] = '<p>Footer text. <a href="http://example.com" style="color:#aaaaaa;">link</a></p>';
     $output = Footer::render($this->block);
     expect($output)->contains('<a href="http://example.com" style="color:#aaaaaa;text-decoration:none">link</a>');
diff --git a/tests/unit/Newsletter/Renderer/Blocks/HeaderTest.php b/tests/unit/Newsletter/Renderer/Blocks/HeaderTest.php
index c13db8de7a..273e61811e 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/HeaderTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/HeaderTest.php
@@ -24,7 +24,7 @@ class HeaderTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Header::render($this->block);
     $expected_result = '
       <tr>
@@ -35,7 +35,7 @@ class HeaderTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItRendersBackgroundColorCorrectly() {
+  public function testItRendersBackgroundColorCorrectly() {
     $this->block['styles']['block']['backgroundColor'] = '#f0f0f0';
     $output = Header::render($this->block);
     $expected_result = '
@@ -47,7 +47,7 @@ class HeaderTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItPrefersInlinedCssForLinks() {
+  public function testItPrefersInlinedCssForLinks() {
     $this->block['text'] = '<p>Header text. <a href="http://example.com" style="color:#aaaaaa;">link</a></p>';
     $output = Footer::render($this->block);
     expect($output)->contains('<a href="http://example.com" style="color:#aaaaaa;text-decoration:underline">link</a>');
diff --git a/tests/unit/Newsletter/Renderer/Blocks/ImageTest.php b/tests/unit/Newsletter/Renderer/Blocks/ImageTest.php
index 7d5de08f5b..43318042d7 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/ImageTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/ImageTest.php
@@ -19,7 +19,7 @@ class ImageTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Image::render($this->block, 200);
     $expected_result = '
       <tr>
@@ -30,7 +30,7 @@ class ImageTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItRendersWithoutLink() {
+  public function testItRendersWithoutLink() {
     $this->block['link'] = null;
     $output = Image::render($this->block, 200);
     $expected_result = '
diff --git a/tests/unit/Newsletter/Renderer/Blocks/SocialTest.php b/tests/unit/Newsletter/Renderer/Blocks/SocialTest.php
index bf3f4b80d6..bd738aef54 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/SocialTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/SocialTest.php
@@ -34,23 +34,23 @@ class SocialTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Social::render($this->block);
     $expected_result = '
       <tr>
         <td class="mailpoet_padded_side mailpoet_padded_vertical" valign="top" align="center">
           <a href="http://www.facebook.com" style="text-decoration:none!important;"
-        ><img 
+        ><img
           src="http://mailpoet.localhost/Facebook.png"
-          width="32" 
-          height="32" 
+          width="32"
+          height="32"
           style="width:32px;height:32px;-ms-interpolation-mode:bicubic;border:0;display:inline;outline:none;"
           alt="facebook"
         ></a>&nbsp;<a href="" style="text-decoration:none!important;"
-        ><img 
+        ><img
           src="http://mailpoet.localhost/Twitter.png"
-          width="36" 
-          height="36" 
+          width="36"
+          height="36"
           style="width:36px;height:36px;-ms-interpolation-mode:bicubic;border:0;display:inline;outline:none;"
           alt="twitter"
         ></a>&nbsp;
diff --git a/tests/unit/Newsletter/Renderer/Blocks/SpacerTest.php b/tests/unit/Newsletter/Renderer/Blocks/SpacerTest.php
index b8d1c539fd..9085a0028f 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/SpacerTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/SpacerTest.php
@@ -14,7 +14,7 @@ class SpacerTest extends \MailPoetUnitTest {
     ],
   ];
 
-  function testItRendersCorrectly() {
+  public function testItRendersCorrectly() {
     $output = Spacer::render($this->block);
     $expected_result = '
       <tr>
@@ -23,7 +23,7 @@ class SpacerTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testsItRendersWithBackground() {
+  public function testsItRendersWithBackground() {
     $this->block['styles']['block']['backgroundColor'] = "#ffffff";
     $output = Spacer::render($this->block);
     $expected_result = '
diff --git a/tests/unit/Newsletter/Renderer/Blocks/TextTest.php b/tests/unit/Newsletter/Renderer/Blocks/TextTest.php
index 11a408d98a..9619c797d2 100644
--- a/tests/unit/Newsletter/Renderer/Blocks/TextTest.php
+++ b/tests/unit/Newsletter/Renderer/Blocks/TextTest.php
@@ -14,12 +14,12 @@ class TextTest extends \MailPoetUnitTest {
   /** @var pQuery */
   private $parser;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->parser = new pQuery;
   }
 
-  function testItRendersPlainText() {
+  public function testItRendersPlainText() {
     $output = Text::render($this->block);
     $expected_result = '
       <tr>
@@ -30,7 +30,7 @@ class TextTest extends \MailPoetUnitTest {
     expect($output)->equals($expected_result);
   }
 
-  function testItRendersParagraph() {
+  public function testItRendersParagraph() {
     $this->block['text'] = '<p>Text</p>';
     $output = Text::render($this->block);
     $table = $this->parser->parseStr($output)->query('table');
@@ -45,7 +45,7 @@ class TextTest extends \MailPoetUnitTest {
     expect($paragraph_table)->equals($expected_result);
   }
 
-  function testItRendersList() {
+  public function testItRendersList() {
     $this->block['text'] = '<ul><li>Item 1</li><li>Item 2</li></ul>';
     $output = Text::render($this->block);
     $ul = $this->parser->parseStr($output)->query('ul');
@@ -55,7 +55,7 @@ class TextTest extends \MailPoetUnitTest {
     expect($list)->equals($expected_result);
   }
 
-  function testItRendersBlockquotes() {
+  public function testItRendersBlockquotes() {
     $this->block['text'] = '<blockquote><p>Quote</p></blockquote>';
     $output = Text::render($this->block);
     $table = $this->parser->parseStr($output)->query('table');
@@ -80,14 +80,14 @@ class TextTest extends \MailPoetUnitTest {
     expect($blockquote_table)->equals($expected_result);
   }
 
-  function testItStylesHeadings() {
+  public function testItStylesHeadings() {
     $this->block['text'] = '<h1>Heading</h1><h2>Heading 2</h2>';
     $output = Text::render($this->block);
     expect($output)->contains('<h1 style="text-align:left;padding:0;font-style:normal;font-weight:normal;">Heading</h1>');
     expect($output)->contains('<h2 style="text-align:left;padding:0;font-style:normal;font-weight:normal;">Heading 2</h2>');
   }
 
-  function testItRemovesLastLineBreak() {
+  public function testItRemovesLastLineBreak() {
     $this->block['text'] = 'hello<br />';
     $output = Text::render($this->block);
     expect($output)->notContains('<br />');
diff --git a/tests/unit/Newsletter/Renderer/EscapeHelperTest.php b/tests/unit/Newsletter/Renderer/EscapeHelperTest.php
index 4c5db73823..02e6afac12 100644
--- a/tests/unit/Newsletter/Renderer/EscapeHelperTest.php
+++ b/tests/unit/Newsletter/Renderer/EscapeHelperTest.php
@@ -6,17 +6,17 @@ use MailPoet\Newsletter\Renderer\EscapeHelper as EHelper;
 
 class EscapeHelperTest extends \MailPoetUnitTest {
 
-  function testItEscapesHtmlText() {
+  public function testItEscapesHtmlText() {
     expect(EHelper::escapeHtmlText('Text<tag>\'"Hello</tag>'))
       ->equals("Text&lt;tag&gt;'\"Hello&lt;/tag&gt;");
   }
 
-  function testItEscapesHtmlAttr() {
+  public function testItEscapesHtmlAttr() {
     expect(EHelper::escapeHtmlAttr('Text<tag>\'"Hello</tag>'))
       ->equals("Text&lt;tag&gt;&#039;&quot;Hello&lt;/tag&gt;");
   }
 
-  function testItEscapesLinkAttr() {
+  public function testItEscapesLinkAttr() {
     expect(EHelper::escapeHtmlLinkAttr('Text<tag>\'"Hello</tag>'))
       ->equals("Text&lt;tag&gt;&#039;&quot;Hello&lt;/tag&gt;");
     expect(EHelper::escapeHtmlLinkAttr('javaScRipt:Text<tag>\'"Hello</tag>'))
diff --git a/tests/unit/Newsletter/Renderer/PreprocessorTest.php b/tests/unit/Newsletter/Renderer/PreprocessorTest.php
index c123c85e55..8df5e99846 100644
--- a/tests/unit/Newsletter/Renderer/PreprocessorTest.php
+++ b/tests/unit/Newsletter/Renderer/PreprocessorTest.php
@@ -9,7 +9,7 @@ use MailPoet\WooCommerce\TransactionalEmails;
 
 class PreprocessorTest extends \MailPoetUnitTest {
 
-  function testProcessWooCommerceHeadingBlock() {
+  public function testProcessWooCommerceHeadingBlock() {
     $renderer = Stub::make(Renderer::class);
     $transactional_emails = Stub::make(TransactionalEmails::class, [
       'getWCEmailSettings' => [
@@ -40,7 +40,7 @@ class PreprocessorTest extends \MailPoetUnitTest {
     ]]);
   }
 
-  function testProcessWooCommerceContentBlock() {
+  public function testProcessWooCommerceContentBlock() {
     $renderer = Stub::make(Renderer::class);
     $preprocessor = new Preprocessor($renderer, Stub::make(TransactionalEmails::class));
     expect($preprocessor->processBlock(['type' => 'woocommerceContent']))->equals([[
diff --git a/tests/unit/Newsletter/Renderer/StylesHelperTest.php b/tests/unit/Newsletter/Renderer/StylesHelperTest.php
index 869177e825..b816cd68ae 100644
--- a/tests/unit/Newsletter/Renderer/StylesHelperTest.php
+++ b/tests/unit/Newsletter/Renderer/StylesHelperTest.php
@@ -6,7 +6,7 @@ use MailPoet\Newsletter\Renderer\StylesHelper;
 
 class StylesHelperTest extends \MailPoetUnitTest {
 
-  function testItGetsCustomFontsLinks() {
+  public function testItGetsCustomFontsLinks() {
     $styles_with_custom_fonts = [
       "text" => [
         "fontColor" => "#565656",
diff --git a/tests/unit/Referrals/ReferralDetectorTest.php b/tests/unit/Referrals/ReferralDetectorTest.php
index e72279b00a..f047851b67 100644
--- a/tests/unit/Referrals/ReferralDetectorTest.php
+++ b/tests/unit/Referrals/ReferralDetectorTest.php
@@ -14,7 +14,7 @@ class ReferralDetectorTest extends \MailPoetUnitTest {
   /** @var WPFunctions&MockObject */
   private $wp_mock;
 
-  function _before() {
+  public function _before() {
     $this->settings_mock = $this->createMock(SettingsController::class);
     $this->wp_mock = $this->createMock(WPFunctions::class);
     if (!defined(ReferralDetector::REFERRAL_CONSTANT_NAME)) {
@@ -22,7 +22,7 @@ class ReferralDetectorTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItPrefersSettingsValue() {
+  public function testItPrefersSettingsValue() {
     $this->settings_mock
       ->expects($this->once())
       ->method('get')
@@ -34,7 +34,7 @@ class ReferralDetectorTest extends \MailPoetUnitTest {
     expect($referral_detector->detect())->equals('settings_referral_id');
   }
 
-  function testItPrefersOptionValueToConstantAndStoresValueToSettings() {
+  public function testItPrefersOptionValueToConstantAndStoresValueToSettings() {
     $this->settings_mock
       ->expects($this->once())
       ->method('get')
@@ -51,7 +51,7 @@ class ReferralDetectorTest extends \MailPoetUnitTest {
     expect($referral_detector->detect())->equals('option_referral_id');
   }
 
-  function testItCanReadConstantAndStoreValueToSettings() {
+  public function testItCanReadConstantAndStoreValueToSettings() {
     $this->settings_mock
       ->expects($this->once())
       ->method('get')
diff --git a/tests/unit/Services/SPFCheckTest.php b/tests/unit/Services/SPFCheckTest.php
index af7fd273a7..3149ae1a75 100644
--- a/tests/unit/Services/SPFCheckTest.php
+++ b/tests/unit/Services/SPFCheckTest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Services;
 
 class SPFCheckTest extends \MailPoetUnitTest {
-  function testItChecksSPFRecord() {
+  public function testItChecksSPFRecord() {
     $domain = 'example.com';
     // Failed to get DNS records
     $response = false;
diff --git a/tests/unit/Settings/CharsetsTest.php b/tests/unit/Settings/CharsetsTest.php
index 75f35a6343..b1da6323dd 100644
--- a/tests/unit/Settings/CharsetsTest.php
+++ b/tests/unit/Settings/CharsetsTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Settings;
 use MailPoet\Settings\Charsets;
 
 class CharsetsTest extends \MailPoetUnitTest {
-  function testItReturnsAListOfCharsets() {
+  public function testItReturnsAListOfCharsets() {
     $charsets = Charsets::getAll();
     expect($charsets)->notEmpty();
     expect($charsets[0])->equals('UTF-8');
diff --git a/tests/unit/Settings/HostsTest.php b/tests/unit/Settings/HostsTest.php
index 4baf7caba5..714d844913 100644
--- a/tests/unit/Settings/HostsTest.php
+++ b/tests/unit/Settings/HostsTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Settings;
 use MailPoet\Settings\Hosts;
 
 class HostsTest extends \MailPoetUnitTest {
-  function testItReturnsAListOfWebHosts() {
+  public function testItReturnsAListOfWebHosts() {
     $web_hosts = Hosts::getWebHosts();
     expect($web_hosts)->notEmpty();
 
@@ -15,7 +15,7 @@ class HostsTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItReturnsAListOfSMTPHosts() {
+  public function testItReturnsAListOfSMTPHosts() {
     $smtp_hosts = Hosts::getSMTPHosts();
     expect($smtp_hosts)->notEmpty();
 
diff --git a/tests/unit/Subscribers/ImportExport/Import/MailChimpTest.php b/tests/unit/Subscribers/ImportExport/Import/MailChimpTest.php
index 92309d4a75..c4efd452aa 100644
--- a/tests/unit/Subscribers/ImportExport/Import/MailChimpTest.php
+++ b/tests/unit/Subscribers/ImportExport/Import/MailChimpTest.php
@@ -16,14 +16,14 @@ class MailChimpTest extends \MailPoetUnitTest {
   /** @var array */
   private $lists;
 
-  function __construct() {
+  public function __construct() {
     parent::__construct();
     $this->api_key = getenv('WP_TEST_IMPORT_MAILCHIMP_API');
     $this->mailchimp = new MailChimp($this->api_key);
     $this->lists = explode(",", getenv('WP_TEST_IMPORT_MAILCHIMP_LISTS'));
   }
 
-  function _before() {
+  public function _before() {
     WPFunctions::set(Stub::make(new WPFunctions, [
       '__' => function ($value) {
         return $value;
@@ -31,7 +31,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     ]));
   }
 
-  function testItCanGetAPIKey() {
+  public function testItCanGetAPIKey() {
     $valid_api_key_format = '12345678901234567890123456789012-ab1';
     // key must consist of two parts separated by hyphen
     expect($this->mailchimp->getAPIKey('invalid_api_key_format'))->false();
@@ -49,14 +49,14 @@ class MailChimpTest extends \MailPoetUnitTest {
       ->equals($valid_api_key_format);
   }
 
-  function testItCanGetDatacenter() {
+  public function testItCanGetDatacenter() {
     $valid_api_key_format = '12345678901234567890123456789012-ab1';
     $data_center = 'ab1';
     expect($this->mailchimp->getDataCenter($valid_api_key_format))
       ->equals($data_center);
   }
 
-  function testItFailsWithIncorrectAPIKey() {
+  public function testItFailsWithIncorrectAPIKey() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
 
     try {
@@ -69,7 +69,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItCanGetLists() {
+  public function testItCanGetLists() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     try {
       $lists = $this->mailchimp->getLists();
@@ -81,7 +81,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     expect($lists[0]['name'])->notEmpty();
   }
 
-  function testItFailsWithIncorrectLists() {
+  public function testItFailsWithIncorrectLists() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
 
     try {
@@ -99,7 +99,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItCanGetSubscribers() {
+  public function testItCanGetSubscribers() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
 
     try {
@@ -115,7 +115,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     expect($subscribers['subscribersCount'])->equals(1);
   }
 
-  function testItFailsWhenSubscribersDataTooLarge() {
+  public function testItFailsWhenSubscribersDataTooLarge() {
     if (getenv('WP_TEST_ENABLE_NETWORK_TESTS') !== 'true') $this->markTestSkipped();
     $mailchimp = clone($this->mailchimp);
     $mailchimp->max_post_size = 10;
@@ -129,7 +129,7 @@ class MailChimpTest extends \MailPoetUnitTest {
     }
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/unit/Subscription/BlacklistTest.php b/tests/unit/Subscription/BlacklistTest.php
index 1b687bc991..a7889e9b4e 100644
--- a/tests/unit/Subscription/BlacklistTest.php
+++ b/tests/unit/Subscription/BlacklistTest.php
@@ -3,7 +3,7 @@
 namespace MailPoet\Subscription;
 
 class BlacklistTest extends \MailPoetUnitTest {
-  function testItChecksBlacklistedEmails() {
+  public function testItChecksBlacklistedEmails() {
     $email = 'test@example.com';
     $domain = 'example.com';
     $blacklist = new Blacklist();
diff --git a/tests/unit/Util/DOMTest.php b/tests/unit/Util/DOMTest.php
index ef9f67e237..394ac0942c 100644
--- a/tests/unit/Util/DOMTest.php
+++ b/tests/unit/Util/DOMTest.php
@@ -9,11 +9,11 @@ class DOMTest extends \MailPoetUnitTest {
   /** @var pQuery\DomNode */
   private $root;
 
-  function _before() {
+  public function _before() {
     $this->root = pQuery::parseStr('<p><i>italic</i><em>previous text<a href="#mylink"><img src="#myimage" /></a>next text</em><b>bolded</b></p>');
   }
 
-  function testItDeepSplitsDOMTreeByElement() {
+  public function testItDeepSplitsDOMTreeByElement() {
     $a = $this->root->query('a');
     assert($a instanceof pQuery);
     DOMUtil::splitOn($this->root, $a->offsetGet(0));
@@ -25,7 +25,7 @@ class DOMTest extends \MailPoetUnitTest {
     );
   }
 
-  function testItFindsTopAncestor() {
+  public function testItFindsTopAncestor() {
     $img = $this->root->query('img');
     assert($img instanceof pQuery);
     $image = $img->offsetGet(0);
diff --git a/tests/unit/Util/HelpersTest.php b/tests/unit/Util/HelpersTest.php
index de83953527..87dfe2c60e 100644
--- a/tests/unit/Util/HelpersTest.php
+++ b/tests/unit/Util/HelpersTest.php
@@ -5,14 +5,14 @@ namespace MailPoet\Test\Util;
 use MailPoet\Util\Helpers;
 
 class HelpersTest extends \MailPoetUnitTest {
-  function testItReplacesLinkTags() {
+  public function testItReplacesLinkTags() {
     $source = '[link]example link[/link]';
     $link = 'http://example.com';
     expect(Helpers::replaceLinkTags($source, $link))
       ->equals('<a href="' . $link . '">example link</a>');
   }
 
-  function testItReplacesLinkTagsAndAddsAttributes() {
+  public function testItReplacesLinkTagsAndAddsAttributes() {
     $source = '[link]example link[/link]';
     $link = 'http://example.com';
     $attributes = [
@@ -23,20 +23,20 @@ class HelpersTest extends \MailPoetUnitTest {
       ->equals('<a class="test class" target="_blank" href="' . $link . '">example link</a>');
   }
 
-  function testItAcceptsCustomLinkTag() {
+  public function testItAcceptsCustomLinkTag() {
     $source = '[custom_link_tag]example link[/custom_link_tag]';
     $link = 'http://example.com';
     expect(Helpers::replaceLinkTags($source, $link, [], 'custom_link_tag'))
       ->equals('<a href="' . $link . '">example link</a>');
   }
 
-  function testItChecksForValidJsonString() {
+  public function testItChecksForValidJsonString() {
     expect(Helpers::isJson(123))->false();
     $json = json_encode(['one' => 1, 'two' => 2]);
     expect(Helpers::isJson($json))->true();
   }
 
-  function testItTrimStringsRecursively() {
+  public function testItTrimStringsRecursively() {
     expect(Helpers::recursiveTrim('  foo'))->equals('foo');
     expect(Helpers::recursiveTrim('foo  '))->equals('foo');
     expect(Helpers::recursiveTrim(123))->equals(123);
diff --git a/tests/unit/Util/License/Features/SubscribersTest.php b/tests/unit/Util/License/Features/SubscribersTest.php
index b34e81f22b..738f7a72b8 100644
--- a/tests/unit/Util/License/Features/SubscribersTest.php
+++ b/tests/unit/Util/License/Features/SubscribersTest.php
@@ -10,7 +10,7 @@ use MailPoet\Util\License\Features\Subscribers as SubscribersFeature;
 
 class SubscribersTest extends \MailPoetUnitTest {
 
-  function testCheckReturnsTrueIfOldUserReachedLimit() {
+  public function testCheckReturnsTrueIfOldUserReachedLimit() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => false,
       'has_premium_key' => false,
@@ -20,7 +20,7 @@ class SubscribersTest extends \MailPoetUnitTest {
     expect($subscribers_feature->check())->true();
   }
 
-  function testCheckReturnsFalseIfOldUserDidntReachLimit() {
+  public function testCheckReturnsFalseIfOldUserDidntReachLimit() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => false,
       'has_premium_key' => false,
@@ -30,7 +30,7 @@ class SubscribersTest extends \MailPoetUnitTest {
     expect($subscribers_feature->check())->false();
   }
 
-  function testCheckReturnsTrueIfNewUserReachedLimit() {
+  public function testCheckReturnsTrueIfNewUserReachedLimit() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => false,
       'has_premium_key' => false,
@@ -40,7 +40,7 @@ class SubscribersTest extends \MailPoetUnitTest {
     expect($subscribers_feature->check())->true();
   }
 
-  function testCheckReturnsFalseIfNewUserDidntReachLimit() {
+  public function testCheckReturnsFalseIfNewUserDidntReachLimit() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => false,
       'has_premium_key' => false,
@@ -50,7 +50,7 @@ class SubscribersTest extends \MailPoetUnitTest {
     expect($subscribers_feature->check())->false();
   }
 
-  function testCheckReturnsFalseIfMSSKeyExists() {
+  public function testCheckReturnsFalseIfMSSKeyExists() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => true,
       'has_premium_key' => false,
@@ -60,7 +60,7 @@ class SubscribersTest extends \MailPoetUnitTest {
     expect($subscribers_feature->check())->false();
   }
 
-  function testCheckReturnsFalseIfPremiumKeyExists() {
+  public function testCheckReturnsFalseIfPremiumKeyExists() {
     $subscribers_feature = $this->constructWith([
       'has_mss_key' => false,
       'has_premium_key' => true,
diff --git a/tests/unit/Util/License/LicenseTest.php b/tests/unit/Util/License/LicenseTest.php
index b6dc5f03fb..1815bfbc38 100644
--- a/tests/unit/Util/License/LicenseTest.php
+++ b/tests/unit/Util/License/LicenseTest.php
@@ -5,7 +5,7 @@ namespace MailPoet\Test\Util\License;
 use MailPoet\Util\License\License;
 
 class LicenseTest extends \MailPoetUnitTest {
-  function testItGetsLicense() {
+  public function testItGetsLicense() {
     if (defined('MAILPOET_PREMIUM_LICENSE')) return;
     expect(License::getLicense())->false();
     expect(License::getLicense('valid'))->equals('valid');
diff --git a/tests/unit/Util/PQueryTest.php b/tests/unit/Util/PQueryTest.php
index 6e093e1a22..26448a1f1f 100644
--- a/tests/unit/Util/PQueryTest.php
+++ b/tests/unit/Util/PQueryTest.php
@@ -5,14 +5,14 @@ namespace MailPoet\Test\Util;
 use MailPoet\Util\pQuery\pQuery;
 
 class PQueryTest extends \MailPoetUnitTest {
-  function testBreakingQuoteAreNotRendered() {
+  public function testBreakingQuoteAreNotRendered() {
     $html = '<a href="#" title="Escape " this"></a>';
     $domnode = pQuery::parseStr($html);
     $inner_text = $domnode->getInnerText();
     expect($inner_text)->equals("");
   }
 
-  function testQuotesAreCorrectlyEscaped() {
+  public function testQuotesAreCorrectlyEscaped() {
     $html_characters = ['&quot;', '&#34;', '&#39;'];
 
     foreach ($html_characters as $char) {
@@ -20,7 +20,7 @@ class PQueryTest extends \MailPoetUnitTest {
     }
   }
 
-  function testEncodedHtmlNamesAreDecoded() {
+  public function testEncodedHtmlNamesAreDecoded() {
     $html_names = ['&amp;', '&lt;', '&gt;', '&nbsp;', '&iexcl;', '&cent;', '&pound;', '&curren;', '&yen;', '&brvbar;', '&sect;', '&uml;', '&copy;', '&ordf;', '&laquo;', '&not;', '&shy;', '&reg;', '&macr;', '&deg;', '&plusmn;', '&sup2;', '&sup3;', '&acute;', '&micro;', '&para;', '&middot;', '&cedil;', '&sup1;', '&ordm;', '&raquo;', '&frac14;', '&frac12;', '&frac34;', '&iquest;', '&Agrave;', '&Aacute;', '&Acirc;', '&Atilde;', '&Auml;', '&Aring;', '&AElig;', '&Ccedil;', '&Egrave;', '&Eacute;', '&Ecirc;', '&Euml;', '&Igrave;', '&Iacute;', '&Icirc;', '&Iuml;', '&ETH;', '&Ntilde;', '&Ograve;', '&Oacute;', '&Ocirc;', '&Otilde;', '&Ouml;', '&times;', '&Oslash;', '&Ugrave;', '&Uacute;', '&Ucirc;', '&Uuml;', '&Yacute;', '&THORN;', '&szlig;', '&agrave;', '&aacute;', '&acirc;', '&atilde;', '&auml;', '&aring;', '&aelig;', '&ccedil;', '&egrave;', '&eacute;', '&ecirc;', '&euml;', '&igrave;', '&iacute;', '&icirc;', '&iuml;', '&eth;', '&ntilde;', '&ograve;', '&oacute;', '&ocirc;', '&otilde;', '&ouml;', '&divide;', '&oslash;', '&ugrave;', '&uacute;', '&ucirc;', '&uuml;', '&yacute;', '&thorn;', '&yuml;'];
 
     foreach ($html_names as $char) {
@@ -28,7 +28,7 @@ class PQueryTest extends \MailPoetUnitTest {
     }
   }
 
-  function testEncodedHtmlNumbersAreDecoded() {
+  public function testEncodedHtmlNumbersAreDecoded() {
     // Tested numbers are from https://www.ascii.cl/htmlcodes.htm
     $html_numbers = array_merge(range(40, 126), range(160, 255), [32, 33, 35, 36, 37, 38, 338, 339, 352, 353, 376, 402, 8211, 8212, 8216, 8217, 8218, 8220, 8221, 8222, 8224, 8225, 8226, 8230, 8240, 8364, 8482]);
 
@@ -37,7 +37,7 @@ class PQueryTest extends \MailPoetUnitTest {
     }
   }
 
-  function testItCanParseRealHtmlSnippets() {
+  public function testItCanParseRealHtmlSnippets() {
     $snippets = [
       '<table width="100%" border="0" cellpadding="0" cellspacing="0" class="mailpoet_cols-one" style="border-spacing:0;mso-table-lspace:0;mso-table-rspace:0;table-layout:fixed;margin-left:auto;margin-right:auto;padding-left:0;padding-right:0;background-color:#ffffff;border-collapse:collapse" bgcolor="#ffffff"><tbody><tr><td class="mailpoet_header_footer_padded mailpoet_header" style="line-height:19.2px;text-align:center ;color:#222222 ;font-family:Arial ;font-size:12px ;border-collapse:collapse;padding:10px 20px"> <a href="http://littlespree.com?mailpoet_router&endpoint=track&action=click&data=WyIyMjIwIiwiZDE0Zjc3IiwiMTA4IiwiMTBiYjc1ZDhiZjgxIixmYWxzZV0" style="color:#6cb7d4 ;text-decoration:underline ">View this newsletter in your browser.</a></td></tr></tbody></table>',
       '<td class="mailpoet_spacer" height="30" valign="top" style="border-collapse:collapse"></td>',
@@ -55,7 +55,7 @@ class PQueryTest extends \MailPoetUnitTest {
     }
   }
 
-  function parseTest($html, $equals = true) {
+  public function parseTest($html, $equals = true) {
     $parsed_html = pQuery::parseStr($html)->getInnerText();
     if ($equals) {
       expect($parsed_html)->equals($html);
diff --git a/tests/unit/Util/SecondLevelDomainNamesTest.php b/tests/unit/Util/SecondLevelDomainNamesTest.php
index f5f4319aeb..ca5560a154 100644
--- a/tests/unit/Util/SecondLevelDomainNamesTest.php
+++ b/tests/unit/Util/SecondLevelDomainNamesTest.php
@@ -7,28 +7,28 @@ class SecondLevelDomainNamesTest extends \MailPoetUnitTest {
   /** @var SecondLevelDomainNames */
   private $extractor;
 
-  function _before() {
+  public function _before() {
     parent::_before();
     $this->extractor = new SecondLevelDomainNames();
   }
 
-  function testItGetsSecondLevelDomainName() {
+  public function testItGetsSecondLevelDomainName() {
     expect($this->extractor->get('mailpoet.com'))->equals('mailpoet.com');
   }
 
-  function testItGetsSecondLevelDomainNameFromThirdLevel() {
+  public function testItGetsSecondLevelDomainNameFromThirdLevel() {
     expect($this->extractor->get('newsletters.mailpoet.com'))->equals('mailpoet.com');
   }
 
-  function testItGetsSecondLevelDomainNameWithCoUk() {
+  public function testItGetsSecondLevelDomainNameWithCoUk() {
     expect($this->extractor->get('example.co.uk'))->equals('example.co.uk');
   }
 
-  function testItGetsSecondLevelDomainNameFromThirdLevelWithCoUk() {
+  public function testItGetsSecondLevelDomainNameFromThirdLevelWithCoUk() {
     expect($this->extractor->get('test.example.co.uk'))->equals('example.co.uk');
   }
 
-  function testItGetsSecondLevelDomainNameForLocalhost() {
+  public function testItGetsSecondLevelDomainNameForLocalhost() {
     expect($this->extractor->get('localhost'))->equals('localhost');
   }
 }
diff --git a/tests/unit/Util/SecurityTest.php b/tests/unit/Util/SecurityTest.php
index afc8d6f68f..aa5ae26b94 100644
--- a/tests/unit/Util/SecurityTest.php
+++ b/tests/unit/Util/SecurityTest.php
@@ -6,7 +6,7 @@ use MailPoet\Util\Security;
 
 class SecurityTest extends \MailPoetUnitTest {
 
-  function testItCanGenerateARandomString() {
+  public function testItCanGenerateARandomString() {
     // it has a default length of 5
     $hash = Security::generateRandomString();
     expect(strlen($hash))->equals(5);
@@ -24,14 +24,14 @@ class SecurityTest extends \MailPoetUnitTest {
     expect(ctype_alnum($long_hash))->true();
   }
 
-  function testItGeneratesRandomHash() {
+  public function testItGeneratesRandomHash() {
     $hash_1 = Security::generateHash();
     $hash_2 = Security::generateHash();
     expect($hash_1)->notEquals($hash_2);
     expect(strlen($hash_1))->equals(Security::HASH_LENGTH);
   }
 
-  function testItGeneratesRandomHashWithCustomLength() {
+  public function testItGeneratesRandomHashWithCustomLength() {
     expect(strlen(Security::generateHash(10)))->equals(10);
   }
 }
\ No newline at end of file
diff --git a/tests/unit/Util/UrlTest.php b/tests/unit/Util/UrlTest.php
index a726f67c55..1ef6643c2c 100644
--- a/tests/unit/Util/UrlTest.php
+++ b/tests/unit/Util/UrlTest.php
@@ -7,7 +7,7 @@ use MailPoet\Util\Url;
 use MailPoet\WP\Functions as WPFunctions;
 
 class UrlTest extends \MailPoetUnitTest {
-  function testCurrentUrlReturnsHomeUrlOnHome() {
+  public function testCurrentUrlReturnsHomeUrlOnHome() {
     $home_url = 'http://example.com';
     $url_helper = new Url(Stub::make(new WPFunctions(), [
       'homeUrl' => $home_url,
diff --git a/tests/unit/WP/DateTimeTest.php b/tests/unit/WP/DateTimeTest.php
index e2e3d155d8..065515e6a2 100644
--- a/tests/unit/WP/DateTimeTest.php
+++ b/tests/unit/WP/DateTimeTest.php
@@ -8,7 +8,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class DateTimeTest extends \MailPoetUnitTest {
 
-  function testGetTimeFormat() {
+  public function testGetTimeFormat() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'getOption' => function($key) {
         return 'H:i';
@@ -24,7 +24,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->getTimeFormat())->equals('H:i:s');
   }
 
-  function testGetDateFormat() {
+  public function testGetDateFormat() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'getOption' => function($key) {
         return 'm-d';
@@ -40,7 +40,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->getDateFormat())->equals('Y-m-d');
   }
 
-  function testGetCurrentDate() {
+  public function testGetCurrentDate() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'currentTime' => function($format) {
         return date($format);
@@ -49,7 +49,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->getCurrentDate("Y-m"))->equals(date("Y-m"));
   }
 
-  function testGetCurrentTime() {
+  public function testGetCurrentTime() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'currentTime' => function($format) {
         return date($format);
@@ -58,7 +58,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->getCurrentTime("i:s"))->regExp('/\d\d:\d\d/');
   }
 
-  function testFormatTime() {
+  public function testFormatTime() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'getOption' => function($key) {
         return 'H:i';
@@ -70,7 +70,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->formatTime($timestamp, $format))->equals(date($format, $timestamp));
   }
 
-  function testFormatDate() {
+  public function testFormatDate() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'getOption' => function($key) {
         return 'm-d';
@@ -82,7 +82,7 @@ class DateTimeTest extends \MailPoetUnitTest {
     expect($date_time->formatDate($timestamp, $format))->equals(date($format, $timestamp));
   }
 
-  function testTimeInterval() {
+  public function testTimeInterval() {
     $date_time = new WPDateTime(Stub::make(new WPFunctions(), [
       'getOption' => function($key) {
         return 'H:i';
diff --git a/tests/unit/WP/PostsTest.php b/tests/unit/WP/PostsTest.php
index 530a1a7bcf..4666b3b24f 100644
--- a/tests/unit/WP/PostsTest.php
+++ b/tests/unit/WP/PostsTest.php
@@ -8,7 +8,7 @@ use MailPoet\WP\Posts;
 
 class PostsTest extends \MailPoetUnitTest {
 
-  function testGetTermsProxiesCallToWordPress() {
+  public function testGetTermsProxiesCallToWordPress() {
     $args = [
       'taxonomy' => 'post_tags',
       'hide_empty' => true,
@@ -31,7 +31,7 @@ class PostsTest extends \MailPoetUnitTest {
     expect($result['arguments'][0])->equals($args);
   }
 
-  function testGetTermsPassesTaxonomyAsFirstArgumentInOldVersions() {
+  public function testGetTermsPassesTaxonomyAsFirstArgumentInOldVersions() {
     $args = [
       'taxonomy' => 'post_tags',
       'hide_empty' => true,
@@ -55,7 +55,7 @@ class PostsTest extends \MailPoetUnitTest {
     expect($result['arguments'][1])->equals(array_diff_key($args, ['taxonomy' => '']));
   }
 
-  function _after() {
+  public function _after() {
     WPFunctions::set(new WPFunctions);
   }
 }
diff --git a/tests/unit/WP/ReadmeTest.php b/tests/unit/WP/ReadmeTest.php
index ae469602d8..527e8051d1 100644
--- a/tests/unit/WP/ReadmeTest.php
+++ b/tests/unit/WP/ReadmeTest.php
@@ -8,24 +8,24 @@ class ReadmeTest extends \MailPoetUnitTest {
   /** @var string */
   private $data;
 
-  function _before() {
+  public function _before() {
     // Sample taken from https://wordpress.org/plugins/about/readme.txt
     $this->data = file_get_contents(dirname(__FILE__) . '/ReadmeTestData.txt');
   }
 
-  function testItParsesChangelog() {
+  public function testItParsesChangelog() {
     $result = Readme::parseChangelog($this->data);
     expect(count($result))->equals(2);
     expect(count($result[0]['changes']))->equals(2);
     expect(count($result[1]['changes']))->equals(1);
   }
 
-  function testItRespectsLimitOfParsedItems() {
+  public function testItRespectsLimitOfParsedItems() {
     $result = Readme::parseChangelog($this->data, 1);
     expect(count($result))->equals(1);
   }
 
-  function testItReturnsFalseOnMalformedData() {
+  public function testItReturnsFalseOnMalformedData() {
     $result = Readme::parseChangelog("");
     expect($result)->false();
     $result = Readme::parseChangelog("== Changelog ==\n\n\n=\n==");
diff --git a/tests/unit/WooCommerce/TransactionalEmailsTest.php b/tests/unit/WooCommerce/TransactionalEmailsTest.php
index 8c9d62f5ab..c82f69244e 100644
--- a/tests/unit/WooCommerce/TransactionalEmailsTest.php
+++ b/tests/unit/WooCommerce/TransactionalEmailsTest.php
@@ -12,7 +12,7 @@ use MailPoet\WP\Functions as WPFunctions;
 
 class TransactionalEmailsTest extends \MailPoetUnitTest {
 
-  function testGetEmailHeadings() {
+  public function testGetEmailHeadings() {
     $wp = Stub::make(new WPFunctions, [
       'getOption' => function($name) {
         if ($name === 'woocommerce_new_order_settings')