/**
  * @see EPSInterface::invalidatePicking()
  */
 public function invalidatePicking($sessionId, $billOfLading, $cancelComment)
 {
     try {
         $invalidatePickingStdObject = new stdClass();
         $invalidatePickingStdObject->sessionId = $sessionId;
         $invalidatePickingStdObject->billOfLading = $billOfLading;
         $invalidatePickingStdObject->cancelComment = $cancelComment;
         parent::invalidatePicking($invalidatePickingStdObject);
     } catch (SoapFault $sf) {
         throw new ServerException($sf);
     }
 }