anchor.diff:  class TextureAnimationElement extends PElement {
     final List<TextureAnimationRequest> _requests = new List<TextureAnimationRequest>();
   
  -  TextureAnimationElement(num width, num height) :
  -    super(width, height);
  +  TextureAnimationElement(num width, num height) : super(width, height);
   
     void add(TextureAnimationRequest request) {
       assert(request != null);
  
positive.code:     }
    }
  
    void drawOverride(CanvasRenderingContext2D ctx) {
      var frameName;
      var offset = _offset;
      if(_frame < 0 && _initialFrame != null) {
  
negative.code: 
    void drawOverride(CanvasRenderingContext2D ctx) {
      for(final r in _requests) {
        final data = r._getFrameDetails();
        final offset = data.item1;
        final frameName = data.item2;
  
        ctx.save();
        ctx.translate(offset.x, offset.y);
        drawTextureKeyAt(ctx, frameName);
        ctx.restore();
      }
    }
  }
  