src/Zf2Forum/Model/Topic/TopicMapper.php
public function persist(TopicInterface $thread)
    {
        if ($thread->getId() > 0) {
            $this->update($thread, null, null, new TopicHydrator());
        } else {
            $this->insert($thread, null, new TopicHydrator());
        }

        return $thread;
    }
public function persist(TopicInterface $thread)
    {
        if ($thread->getId() > 0) {
            $this->update($thread, null, null, new TopicHydrator());
        } else {
            $this->insert($thread, null, new TopicHydrator());
        }

        return $thread;
    }
persist - Persists a thread to the database.

@param TopicInterface $thread
@return TopicInterface