protected function afterSave(ilObject $a_new_object)
 {
     $a_new_object->setOffline(true);
     $a_new_object->setNumberOfSlots(4);
     $a_new_object->update();
     // always send a message
     ilUtil::sendSuccess($this->lng->txt("book_pool_added"), true);
     $this->ctrl->setParameter($this, "ref_id", $a_new_object->getRefId());
     $this->ctrl->redirect($this, "edit");
 }