private function deleteTracker($tracker)
 {
     $tracker_id = $tracker->getId();
     $this->logger->debug('[Tracker] ElasticSearch: deleting all artifacts of tracker #' . $tracker_id);
     try {
         $this->client->getIndexedType($tracker_id);
         $this->client->deleteType($tracker_id);
     } catch (ElasticSearch_TypeNotIndexed $e) {
         $this->logger->debug('[Tracker] ElasticSearch: tracker #' . $tracker_id . ' has not previously been indexed, nothing to delete');
         return;
     }
 }
 private function deleteForProject($project_id)
 {
     $this->logger->debug('deleting all project documents #' . $project_id);
     try {
         $this->client->getIndexedType($project_id);
         $this->client->deleteType($project_id);
     } catch (ElasticSearch_TypeNotIndexed $exception) {
         $this->logger->debug('project #' . $project_id . ' not indexed, nothing to delete');
         return;
     }
 }