function executeUpdateUsergroup(Userinfo $userinfo, Userinfo &$existinguser)
    {
        $changed = false;
        $usergroups = $this->getCorrectUserGroups($userinfo);
		if (!$this->compareUserGroups($existinguser, $usergroups)) {
			$this->updateUsergroup($userinfo, $existinguser);
			$changed = true;
        }
    	return $changed;
    }