anchor.diff:      ev.preventDefault();
     });
   
  +  window.onPopState.listen(
  +    (e) => navigator.navigate(window.location.pathname, true)
  +  );
  +
     // Initialize routing with current url.
     navigator.navigate(window.location.pathname);
   
  
positive.code:       match[1]
      );
      this.activeRoute = match[0];
      this.history.pushState(null, '', url);
  
      // Stop watching parameters of the previous view.
      if (this.activeWatchDisposer != null) {
  
negative.code:    * 5. Starts monitoring [Route] parameters for changes and automatically
     *    updates the [url] with [History.replaceState].
     */
    void navigate(url, [withoutPush = false]) {
      var match = this.router.match(url);
      this.transitionHandler(
        this.views[activeRoute],
  