private static function sanitize_errors($source)
 {
     if (is_array($source)) {
         if ($source && array_key_exists('errors', $source)) {
             foreach ($source['errors'] as &$error) {
                 if (is_array($error)) {
                     $error = self::sanitize_errors($error);
                 } else {
                     $error = ICL_AdminNotifier::sanitize_and_format_message($error);
                 }
             }
             unset($error);
         }
     } else {
         $source = ICL_AdminNotifier::sanitize_and_format_message($source);
     }
     return $source;
 }