public static function isAdmin($user_id = null)
 {
     try {
         $user_id = $user_id ? $user_id : Helper::userId();
         //$user_id = $user_id != NULL ? $user_id : Helper::userId(); // PAG changed because this will be true if $user_id = 0 which is supposed to be false too
         $emails = Admin::getAdmins();
         return in_array(User::email($user_id), $emails);
     } catch (Exception $e) {
         return false;
     }
 }