anchor.diff:    void update({num time}) {
       _resize();
       var delta = time - _lastTime;
  -    delta = min(0.05, delta);
  +    if (useMaxDelta) {
  +      delta = min(0.05, delta);
  +    }
       world.delta = delta;
       _lastTime = time;
       world.process();
  
positive.code:   final String bodyDefsName;
    final String musicName;
    final bool webgl;
    World world;
    Map<String, List<Polygon>> bodyDefs;
    SpriteSheet spriteSheet;
  
negative.code:       this.audioContext,
        this.webgl = false,
        bool depthTest = true,
        bool blending = true,
        this.useMaxDelta = true})
        : canvas = querySelector(canvasSelector),
          helper = GameHelper(appName, audioContext),
          ctx = webgl
  