enum ScrollRestoration { "auto", "manual" };
  
  [Exposed=Window]
  interface History {
  //  readonly attribute unsigned long index;
    readonly attribute unsigned long length;
  //  attribute ScrollRestoration scrollRestoration;
    readonly attribute any state;
    void go(optional long delta = 0);
    void back();
    void forward();
    void pushState(any data, DOMString title, optional USVString? url = null);
    void replaceState(any data, DOMString title, optional USVString? url = null);
  };