protected function redirectToRefId($a_ref_id, $a_cmd = "")
 {
     $obj_type = ilObject::_lookupType($a_ref_id, true);
     if ($obj_type != "orgu") {
         parent::redirectToRefId($a_ref_id, $a_cmd);
     } else {
         $this->ctrl->setParameterByClass("ilObjOrgUnitGUI", "ref_id", $a_ref_id);
         $this->ctrl->redirectByClass("ilObjOrgUnitGUI", $a_cmd);
     }
 }