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) {
      for(final r in _requests) {
        r.drawOverride(ctx);
      }
    }
  }
  
negative.code:     }
    }
  
    Tuple<Coordinate, String> _getFrameDetails() {
      var frameName;
      var offset = _offset;
      if(_frame < 0 && _initialFrame != null) {
  