protected function verifySubscriber($queue, $subscriber_id)
    {
        /** @var User */
        $user = Yii::$app->user;
        $subscribedOnly = $user->can('nfy.message.read.subscribed');
        if ($subscribedOnly && (!$queue->isSubscribed($user->getId()) || $subscriber_id != $user->getId())) {
            throw new ForbiddenHttpException(Yii::t('yii', 'You are not authorized to perform this action.'));
        }
    }