anchor.diff:  
     SnakeState(String n) {
       this.name = n;
  -    this.snake = new Snake(canvas);// XXX Should not be necessary (and is a bogus coupling in any case)
  +    // XXX Should not be necessary (and is a bogus coupling in any case)
  +    this.snake = new Snake(canvas);
     }
   
     onKeyDown(KeyboardEvent event) {
  
positive.code: 
  const int WIDTH = 640;
  const int HEIGHT = 480;
  drawText(CanvasRenderingContext2D canvas, String text, String color) {
    canvas.clearRect(0, 0, WIDTH, HEIGHT);
    canvas.fillStyle = color;
  
negative.code:   }
  
    onRender(GameLoopHtml gameLoop) {
  
      canvas.clearRect(0, 0, WIDTH, HEIGHT);
      canvas.fillStyle = "rgb(255,165,0)";
      canvas.fillRect(0, 0, WIDTH, HEIGHT);
      canvas.font = "italic bold 24px sans-serif";
      canvas.strokeText("Inside snake pen", 0, 100);
  
      canvas.fillRect(0, 0, 20, 20);
      snake.render(canvas);
    }
  
  