static function FindContentGroup(Content $content)
    {
        $result = null;
        $currContent = $content;
        do
        {
            $result = $currContent->GetUserGroup();
            $currContent = ContentTreeUtil::ParentOf($currContent);
        } 
        while (!$result && $currContent);
        if ($result)
        {
            return $result;
        }
        return self::GetUpperContentGroup($content);
    }