public function memberNotInGroups($groupList, $memberGroups = null)
    {
        if (!$memberGroups) {
            $memberGroups = $this->Groups();
        }

        foreach ($memberGroups as $group) {
            if (in_array($group->Code, $groupList)) {
                $index = array_search($group->Code, $groupList);
                unset($groupList[$index]);
            }
        }

        return $groupList;
    }