/**
  * Persists a vote.
  *
  * @param VoteInterface $vote
  * @param VotableCommentInterface $comment
  * @return void
  */
 public function addVote(VoteInterface $vote, VotableCommentInterface $comment)
 {
     $vote->setComment($comment);
     $comment->incrementScore($vote->getvalue());
     $this->em->persist($comment);
     $this->em->persist($vote);
     $this->em->flush();
 }