anchor.diff:    bool get indeterminate => _indeterminate;
     bool _indeterminate = false;
   
  -  /// Actually update the state variables. If both parameters are provided, then
  -  /// set them as presented, otherwise we will clear the other one if necessary.
  -  /// Events are only fired if there was a change and [emitEvent] is true.
  +  /// Actually update the state variables.
  +  ///
  +  /// If both parameters are provided, then set them as presented, otherwise we
  +  /// will clear the other one if necessary. Events are only fired if there was
  +  /// a change and [emitEvent] is true.
     void _setStates(
         {bool checked = false,
         bool indeterminate = false,
  
positive.code:   Icon get icon => _icon;
    Icon _icon = uncheckedIcon;
  
    /// Color of the checkbox.
    @Input()
    String themeColor;
  
  
negative.code:   /// color.
    String get rippleColor => checked ? themeColor : '';
  
    /// Label for the checkbox, alternatively use content.
    @HostBinding('attr.aria-label')
    @Input()
    String label;
  
    /// Toggles checkbox via user action.
    ///
    /// When it is indeterminate, toggle can go to checked or unchecked, depending
    /// on state [indeterminateToChecked].
    @visibleForTesting
    void toggleChecked() {
      if (disabled || readOnly) return;
  