anchor.diff:      Key key,
       this.child,
       this.onTap,
  +    this.onTapDown,
  +    this.onTapCancel,
       this.onDoubleTap,
       this.onLongPress,
       this.onHighlightChanged,
  
positive.code:     _splashes ??= new HashSet<InteractiveInkFeature>();
      _splashes.add(splash);
      _currentSplash = splash;
      updateKeepAlive();
      updateHighlight(true);
    }
  
negative.code: ///
  /// ![The highlight is a rectangle the size of the box.](https://flutter.github.io/assets-for-api-docs/material/ink_well.png)
  ///
  /// The [InkWell] widget must have a [Material] widget as an ancestor. The
  /// [Material] widget is where the ink reactions are actually painted. This
  /// matches the material design premise wherein the [Material] is what is
  /// actually reacting to touches by spreading ink.
  