anchor.diff:  ///
   /// {@tool sample}
   ///
  -/// This example shows a 48x48 green square (placed inside a [Center] widget in
  +/// This example shows a 48x48 amber square (placed inside a [Center] widget in
   /// case the parent widget has its own opinions regarding the size that the
   /// [Container] should take), with a margin so that it stays away from
   /// neighboring widgets:
  
positive.code: /// Center(
  ///   child: Container(
  ///     margin: const EdgeInsets.all(10.0),
  ///     color: const Color(0xFF00FF00),
  ///     width: 48.0,
  ///     height: 48.0,
  ///   ),
  
negative.code: ///     height: Theme.of(context).textTheme.display1.fontSize * 1.1 + 200.0,
  ///   ),
  ///   padding: const EdgeInsets.all(8.0),
  ///   color: Colors.blue[600],
  ///   alignment: Alignment.center,
  ///   child: Text('Hello World',
  ///     style: Theme.of(context)
  ///         .textTheme
  ///         .display1
  ///         .copyWith(color: Colors.white)),
  ///   transform: Matrix4.rotationZ(0.1),
  /// )
  /// ```
  