public function vote()
 {
     $opinionVote = self::POST('opinionVotes/filtered', array('userId' => $this->userId, 'opinionId' => $this->opinionId));
     if (!empty($opinionVote)) {
         if ($this->upDown == $opinionVote->getUpDown()) {
             return;
         } else {
             $this->updateOpinionVote($opinionVote->getId());
         }
     } else {
         $this->addOpinionVote();
     }
     ProductController::updateButtonHighlight($this->opinionId, $this->upDown);
 }