Newscoop\Services\UserTopicService::followTopic PHP Метод

    public function followTopic(User $user, Topic $topic)
    {
        try {
            $this->em->persist(new UserTopic($user, $topic));
            $this->em->flush();
            $this->notify($user, $topic);
        } catch (Exception $e) {
            // ignore if exists
        }
    }