/**
  * Get data from server
  * 
  * @param int $a_server_id
  * @param int $a_econtent_id
  * @param string $a_resource_type
  * @return ilECSEContentDetails
  */
 public static function getInstance($a_server_id, $a_econtent_id, $a_resource_type)
 {
     global $ilLog;
     try {
         include_once './Services/WebServices/ECS/classes/class.ilECSSetting.php';
         include_once './Services/WebServices/ECS/classes/class.ilECSConnector.php';
         $connector = new ilECSConnector(ilECSSetting::getInstanceByServerId($a_server_id));
         $res = $connector->getResource($a_resource_type, $a_econtent_id, true);
         if ($res->getHTTPCode() == ilECSConnector::HTTP_CODE_NOT_FOUND) {
             return;
         }
         if (!is_object($res->getResult())) {
             $ilLog->write(__METHOD__ . ': Error parsing result. Expected result of type array.');
             $ilLog->logStack();
             throw new ilECSConnectorException('error parsing json');
         }
     } catch (ilECSConnectorException $exc) {
         return;
     }
     include_once './Services/WebServices/ECS/classes/class.ilECSEContentDetails.php';
     $details = new self();
     $details->loadFromJSON($res->getResult());
     return $details;
 }