private function SaveRights()
    {
        $userGroup = Usergroup::Schema()->ByID($this->Value('UserGroup'));
        $this->Content()->SetUserGroup($userGroup);
        if (!$userGroup) {
            $oldRights = $this->Content()->GetUserGroupRights();
            if ($oldRights) {
                $oldRights->Delete();
            }
            $this->Content()->SetUserGroupRights(null);
        }
        else {
            $this->contentRights->Save();
            $this->Content()->SetUserGroupRights($this->contentRights->Rights());
        }
        $this->Content()->Save();
    }