anchor.diff:  ///         child: Column(
   ///           mainAxisAlignment: MainAxisAlignment.center,
   ///           children: <Widget>[
  -///             Text(
  +///             const Text(
   ///               'You have pushed the button this many times:',
   ///             ),
   ///             Text(
  
positive.code: ///                 ),
  ///               ),
  ///             ),
  ///             TextField(
  ///               maxLines: 2,
  ///               decoration: InputDecoration(
  ///                 hintText: 'Up/down behave normally here.',
  
negative.code: ///     child: Center(
  ///       child: Shortcuts(
  ///         shortcuts: <LogicalKeySet, Intent>{
  ///           LogicalKeySet(LogicalKeyboardKey.alt, LogicalKeyboardKey.arrowDown): const NextFocusIntent(),
  ///           LogicalKeySet(LogicalKeyboardKey.alt, LogicalKeyboardKey.arrowUp): const PreviousFocusIntent(),
  ///         },
  ///         child: Column(
  ///           children: const <Widget>[
  ///             TextField(
  ///               decoration: InputDecoration(
  ///                 hintText: 'alt + down moves to the next field.',
  