anchor.diff:    bool get checked => _checked;
     bool _checked = false;
   
  +  /// Whether the checkbox can be changed by user interaction.
     @Input()
     bool readOnly = false;
   
  
positive.code:   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.
    void _setStates(
        {bool checked = false,
        bool indeterminate = false,
  
negative.code: /// should only be interactible with SPACE, while button is for both SPACE and
  /// ENTER.
  ///
  /// __Attributes:__
  ///
  /// - `no-ink` -- set this attribute to disable the ripple effect on the chip.
  ///
  @Component(
    selector: 'material-checkbox',
  