static void OnSuccess(Xhr xhr, FnVoidA fn)
        {
            dynamic response = xhr.Response;

            if (fn is FnVoidA)
            {
                fn(response);
            }
        }
        static void Send(string path, FnVoidA fn)
        {
            Xhr xhr = new Xhr
            {
                Method = "GET",
                Url    = string.Format("/data/{0}.json", path)
            };

            xhr.AddListener("success", () => { OnSuccess(xhr, fn); });
            xhr.Send();
        }