Piwik\Notification\Manager::checkId PHP Method

    private static function checkId($id)
    {
        if (empty($id)) {
            throw new \Exception('Notification ID is empty.');
        }
        if (!preg_match('/^(\\w)*$/', $id)) {
            throw new \Exception('Invalid Notification ID given. Only word characters (AlNum + underscore) allowed.');
        }
    }