anchor.diff:  // bool _lights;
   // void setState(VoidCallback fn) { }
   // String _last;
  +// Color _color;
   
   /// Factory for creating gesture recognizers.
   ///
  
positive.code: ///
  /// {@tool snippet}
  ///
  /// This example turns the light bulb yellow when the "turn lights on" button is
  /// tapped by setting the `_lights` field:
  ///
  /// ```dart
  /// Container(
  
negative.code: ///         ),
  ///       ),
  ///     ],
  ///   ),
  /// )
  /// ```
  /// {@end-tool}
  ///
  /// {@tool snippet}
  ///
  /// This example of a [Container] wraps a [GestureDetector] widget.
  /// Since the [GestureDetector] does not have a child it takes on the size of
  /// its parent making the entire area of the surrounding [Container] clickable.
  /// When tapped the [Container] turns yellow by setting the `_color` field:
  ///
  /// ```dart
  /// Container(
  ///   color: _color,
  ///   height: 200.0,
  ///   width: 200.0,
  ///   child: GestureDetector(
  ///     onTap: () {
  ///       setState(() {
  ///         _color = Colors.yellow;
  ///       });
  ///     },
  ///   ),
  /// )
  /// ```
  