src/Zf2Forum/Service/Discuss.php
public function updateMessage(MessageInterface $message)
    {
        $message->setPostTime(new \DateTime);
        return $this->messageMapper->persist($message);
    }
public function updateMessage(MessageInterface $message)
    {
        $message->setPostTime(new \DateTime);
        return $this->messageMapper->persist($message);
    }
updateMessage

@param MessageInterface $message
@return MessageInterface