anchor.diff:  
     @override
     void addToScene(ui.SceneBuilder builder, Offset layerOffset) {
  +    Timeline.startSync('ClipRectLayer::addToScene');
       builder.pushClipRect(clipRect.shift(layerOffset));
       addChildrenToScene(builder, layerOffset);
       builder.pop();
  +    Timeline.finishSync();
     }
   
     @override
  
positive.code: 
    @override
    void addToScene(ui.SceneBuilder builder, Offset layerOffset) {
      Matrix4 offsetTransform = new Matrix4.identity();
      offsetTransform.translate(offset.dx + layerOffset.dx, offset.dy + layerOffset.dy);
      builder.pushTransform((offsetTransform * transform).storage);
      addChildrenToScene(builder, Offset.zero);
      builder.pop();
    }
  
    @override
  
negative.code: 
    @override
    void addToScene(ui.SceneBuilder builder, Offset layerOffset) {
      Timeline.startSync('ShaderMaskLayer::addToScene');
      builder.pushShaderMask(shader, maskRect.shift(layerOffset), transferMode);
      addChildrenToScene(builder, layerOffset);
      builder.pop();
      Timeline.finishSync();
    }
  
    @override
  