/**
  * @see EPSInterface::trackPicking()
  */
 public function trackPicking($sessionId, $billOfLading)
 {
     try {
         $trackPickingStdObject = new stdClass();
         $trackPickingStdObject->sessionId = $sessionId;
         $trackPickingStdObject->billOfLading = $billOfLading;
         $response = parent::trackPicking($trackPickingStdObject);
         $arrResultTrackPicking = array();
         if (isset($response->return)) {
             $arrStdResultTrackPicking = $response->return;
             if (is_array($arrStdResultTrackPicking)) {
                 for ($i = 0; $i < count($arrStdResultTrackPicking); $i++) {
                     $arrResultTrackPicking[$i] = new ResultTrackPicking($arrStdResultTrackPicking[$i]);
                 }
             } else {
                 $arrResultTrackPicking[0] = new ResultTrackPicking($arrStdResultTrackPicking);
             }
         }
         return $arrResultTrackPicking;
     } catch (SoapFault $sf) {
         throw new ServerException($sf);
     }
 }