export function saveTitle(): void {
  void window.history.replaceState(
    extend<Pick<State, State.title>>(
      window.history.state || {},
      {
        title: document.title
      }),
    document.title);
}

export function savePosition(): void {
  void window.history.replaceState(
    extend<Pick<State, State.position>>(
      window.history.state || {},
      {
        position: {
          top: window.pageYOffset,
          left: window.pageXOffset
        }
      }),
    document.title);
}

 it('true', () => {
   assert(hasBinary(new ArrayBuffer(0)) === true);
   assert(hasBinary([new ArrayBuffer(0)]) === true);
   assert(hasBinary({ b: new ArrayBuffer(0) }) === true);
   assert(hasBinary(extend(Object.create(null), { b: new ArrayBuffer(0) })) === true);
 });

 void click(url, event =>
   result = io.router(new Config(extend<Option>({}, option, { replace: '*' })), new RouterEvent(event), process, io));

 .map<Maybe<Config>>(option =>
   option
     ? Just(new Config(extend<Option>({}, config, option)))
     : Nothing)