/**
  * Get timestamp of the last_status according to LP
  *
  * @param srCertificate $cert
  * @return int|null
  */
 protected function getLastLPStatus(srCertificate $cert)
 {
     $ref_id = $cert->getDefinition()->getRefId();
     $obj_id = ilObject::_lookupObjectId($ref_id);
     $lp_data = ilTrQuery::getObjectsDataForUser($cert->getUserId(), $obj_id, $ref_id, '', '', 0, 9999, null, array('last_access'));
     $last_status = null;
     foreach ($lp_data['set'] as $data) {
         if ($data['type'] == 'crs') {
             $last_status = $data['last_access'];
             break;
         }
     }
     return (int) $last_status;
 }