protected static function addEventHandlers()
    {
        $eventManager = EventManager::getInstance();

        foreach (static::$handlers as $module => $handlers) {
            foreach ($handlers as $event => $handler) {
                $eventManager->addEventHandler($module, $event, [__CLASS__, $handler], false, 5000);
            }
        }

        $eventManager->addEventHandler('main', 'OnAfterEpilog', function () {
            $notifier = new Notifier();
            $notifier->deleteNotificationFromPreviousMigration();

            return new EventResult();
        });
    }