anchor.diff:  /// ## Customizing toggle buttons
   /// Each toggle's behavior can be configured by the [onPressed] callback, which
   /// can update the [isSelected] list however it wants to.
  +///
  +/// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_simple.mp4}
   ///
   /// Here is an implementation that allows for multiple buttons to be
   /// simultaneously selected, while requiring none of the buttons to be
  
positive.code: ///   isSelected: isSelected,
  /// ),
  /// ```
  ///
  /// Here is an implementation that requires mutually exclusive selection
  /// while requiring at least one selection. Note that this assumes that
  
negative.code: /// ),
  /// ```
  ///
  /// {@animation 700 150 https://flutter.github.io/assets-for-api-docs/assets/material/toggle_buttons_mutually_exclusive.mp4}
  ///
  /// Here is an implementation that requires mutually exclusive selection,
  /// but allows for none of the buttons to be selected.
  /// ```dart
  