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