anchor.diff:                new GalleryItem(title: 'Tabs', builder: () => new TabsDemo()),
                 new GalleryItem(title: 'Text fields', builder: () => new TextFieldDemo()),
                 new GalleryItem(title: 'Time picker', builder: () => new TimePickerDemo()),
  -              new GalleryItem(title: 'Toolbar', builder: () => new FlexibleSpaceDemo()),
                 new GalleryItem(title: 'Tooltips', builder: () => new TooltipDemo()),
               ]
             ),
  
positive.code:               new GalleryItem(title: "Weather", builder: () => new WeatherDemo()),
                new GalleryItem(title: "Fitness", builder: () => new FitnessDemo()),
                new GalleryItem(title: "Fancy lines", builder: () => new DrawingDemo()),
              ]
            ),
            new TwoLevelSublist(
  
negative.code:             title: new Text("Components"),
              children: <Widget>[
                new GalleryItem(title: 'Buttons', builder: () => new ButtonsDemo()),
                new GalleryItem(title: 'Cards', builder: () => new CardsDemo()),
                new GalleryItem(title: 'Chips', builder: () => new ChipDemo()),
                new GalleryItem(title: 'Date picker', builder: () => new DatePickerDemo()),
  