protected function checkForCycle(Pap_Affiliates_User $potentialParent, $userId) {
     $tree = new Pap_Common_UserTree();
     $tree->startCheckingLoops();
     $affiliate = $potentialParent;
     while ($affiliate != null){
         if ($userId == $affiliate->getId()) {
             return false;
         }
         $affiliate = $tree->getParent($affiliate);
     }
     return true;
 }