public function store(array $data)
    {
        DB::transaction(function() use($data) {
            $model = $this->storeNotificationInstance($data);
            foreach ($data['title'] as $langId => $content) {
                $model->contents()->save($model->contents()->getModel()->newInstance([
                            'notification_id' => $model->id,
                            'lang_id'         => $langId,
                            'title'           => $content,
                            'content'         => $data['content'][$langId],
                            'subject'         => $data['subject'][$langId]
                ]));
            }
        });
    }