private static function GetUpperContentGroup(Content $content)
    {
        if ($content->GetPageContent())
        {
            return self::FindPageGroup($content->GetPageContent()->GetPage());
        }
        else if ($content->GetLayoutContent())
        {
            return $content->GetLayoutContent()->
                        GetArea()->GetLayout()->GetUserGroup();
        }
        else if ($content->GetContainerContent())
        {
            return $content->GetContainerContent()->
                        GetContainer()->GetUserGroup();
        }
        return null;
    }