Settings menu item in stock2 doesn't work

sky/examples/widgets/navigation.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'package:sky/widgets/basic.dart';
 import 'package:sky/widgets/navigator.dart';
 import 'package:sky/widgets/transition.dart';
 import 'package:sky/widgets/raised_button.dart';
 
 List<Route> routes = [
@@ skipping 53 matching lines @@
   )
 ];
 
 class NavigationExampleApp extends App {
   Widget build() {
     return new Flex([new Navigator(routes: routes)]);
   }
 }
 
 void main() {
-  App app = new NavigationExampleApp();
+  runApp(new NavigationExampleApp());
 }