code: function(e) {
        if (this.onbeforeunload && this.onbeforeunload()) {
          var fragment = this.fragment;
          this.fragment = '';
          return this.navigate(fragment, {trigger: false});
        }
        var current = this.getFragment();
        if (current == this.fragment && this.iframe) current = this.getFragment(this.getHash(this.iframe));
        if (current == this.fragment) return false;
        if (this.iframe) this.navigate(current);
        this.loadUrl() || this.loadUrl(this.getHash());
      }
docs: Checks the current URL to see if it has changed, and if it has, calls `loadUrl`, normalizing across the hidden iframe.