Use phpstan level 2

[MAILPOET-1822]

lib/Models/NewsletterLink.php

@@ -3,9 +3,19 @@ namespace MailPoet\Models;
 
 if (!defined('ABSPATH')) exit;
 
+/**
+ * @property int $newsletter_id
+ * @property int $queue_id
+ * @property string $url
+ * @property string $hash
+ */
 class NewsletterLink extends Model {
   public static $_table = MP_NEWSLETTER_LINKS_TABLE;
 
+  /**
+   * @param Newsletter $newsletter
+   * @return \stdClass|null
+   */
   static function findTopLinkForNewsletter(Newsletter $newsletter) {
     $link = self::selectExpr('links.*')
       ->selectExpr('count(*)', 'clicksCount')