anchor.diff:        frameName = "${_texturePrefix}_$frameString.png";
       }
   
  -    ctx.save();
  -    ctx.translate(offset.x, offset.y);
  -    drawTextureKeyAt(ctx, frameName);
  -    ctx.restore();
  +    return new Tuple(offset, frameName);
     }
   }
  
positive.code: 
    void drawOverride(CanvasRenderingContext2D ctx) {
      for(final r in _requests) {
        r.drawOverride(ctx);
      }
    }
  }
  
negative.code: class TextureAnimationElement extends PElement {
    final List<TextureAnimationRequest> _requests = new List<TextureAnimationRequest>();
  
    TextureAnimationElement(num width, num height) : super(width, height);
  
    void add(TextureAnimationRequest request) {
      assert(request != null);
  