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