anchor.diff:      });
     }
   
  -  Widget buildIconButton(double iconSize, IconData icon, bool enabled) {
  -    return new IconButton(
  -      icon: new Icon(icon),
  -      iconSize: iconSize,
  -      tooltip: "${enabled ? 'Enabled' : 'Disabled'} icon button",
  -      onPressed: enabled ? handleIconButtonPress : null
  -    );
  -  }
  -
  -  Widget buildSizeLabel(int size, TextStyle style) {
  -    return new SizedBox(
  -      height: size.toDouble() + 16.0, // to match an IconButton's padded height
  -      child: new Center(
  -        child: new Text('$size', style: style)
  -      )
  -    );
  -  }
  -
     @override
     Widget build(BuildContext context) {
  -    final ThemeData theme = Theme.of(context);
  -    final TextStyle textStyle = theme.textTheme.subhead.copyWith(color: theme.textTheme.caption.color);
  -
       return new Scaffold(
         appBar: new AppBar(
           title: const Text('Icons')
  
positive.code:     );
    }
  }
  
negative.code:           padding: const EdgeInsets.all(24.0),
            child: new Column(
              children: <Widget>[
                new _IconsDemoCard(handleIconButtonPress),
              ],
            ),
          ),
  