anchor.diff:          _lastHighlight = new InkHighlight(
             controller: Material.of(context),
             referenceBox: referenceBox,
  -          color: Theme.of(context).highlightColor,
  +          color: config.highlightColor ?? Theme.of(context).highlightColor,
             shape: config.highlightShape,
             rectCallback: config.getRectCallback(referenceBox),
             onRemoved: () {
  
positive.code:     onLongPress: onLongPress,
      onHighlightChanged: onHighlightChanged,
      containedInkWell: true,
      highlightShape: BoxShape.rectangle
    );
  }
  
negative.code: 
    /// The radius of the ink splash.
    final double radius;
  
    /// The highlight color of the ink response. If this property is null then the
    /// highlight color of the theme will be used.
    final Color highlightColor;
  
    /// The splash color of the ink response. If this property is null then the
    /// splash color of the theme will be used.
    final Color splashColor;
  
    /// The rectangle to use for the highlight effect and for clipping
    /// the splash effects if [containedInkWell] is true.
  