void main() {
 runApp(MaterialApp(
   home: MyAppHome(), // Becomes the route named '/'.
   routes:  {
     '/a': (BuildContext context) => MyPage(title: 'page A'),
     '/b': (BuildContext context) => MyPage(title: 'page B'),
     '/c': (BuildContext context) => MyPage(title: 'page C'),
   },
 ));
}