public function fulfilled(kEventScope $scope)
 {
     if (!kCurrentContext::$serializeCallback) {
         return false;
     }
     if (!parent::fulfilled($scope)) {
         return false;
     }
     // check if queue exists
     $contentParameters = $this->getContentParameters();
     $queueKey = $this->getQueueKey($contentParameters, null, $scope);
     $queueProvider = QueueProvider::getInstance();
     if (!$queueProvider->exists($queueKey)) {
         KalturaLog::debug("Queue [{$queueKey}] doesn't exist.");
         return false;
     }
     return true;
 }