anchor.diff:    /// Mirror to [PhotoView.childSize]
     final Size childSize;
   
  +  /// Mirror to [PhotoView.scaleStateCycle]
  +  final ScaleStateCycle scaleStateCycle;
  +
     /// Mirror to [PhotoView.onTapUp]
     final PhotoViewImageTapUpCallback onTapUp;
   
  
positive.code:       this.controller,
        this.scaleStateController,
        this.basePosition,
        this.onTapUp,
        this.onTapDown})
        : imageProvider = null,
  
negative.code:       this.controller,
        this.scaleStateController,
        this.basePosition,
        this.scaleStateCycle,
        this.onTapUp,
        this.onTapDown})
        : child = null,
  