private function assignParent(Pap_Affiliates_User $affiliate) {
     if ($affiliate->getParentUser() == null && ($parentUserId = Gpf_Settings::get(Pap_Settings::ASSIGN_NON_REFERRED_AFFILIATE_TO)) != '') {
         try {
             $parentUser = new Pap_Affiliates_User();
             $parentUser->setId($parentUserId);
             $parentUser->load();
             $affiliate->setParentUserId($parentUser->getId());
         } catch (Gpf_Exception $e) {
         }
         Gpf_Plugins_Engine::extensionPoint('PostAffiliate.AffiliateForm.assignParent', $affiliate);
     }
 }