public static function root($path = null)
    {
        if (! is_null($path)) {
            if (! $path instanceof KhttpUrl) {
                $path = AnService::get('anahita:http.url', array('url' => $path));
            }

            self::$_root = $path;
        }

        if (is_null(self::$_root)) {
            self::$_root = self::$_base;
        }

        return self::$_root;
    }