anchor.diff:  
       assert(coords.length >= oldLength);
     }
  -
  -
   
     void render(canvas) {
       coords.forEach((c) => renderSquare(c, white_color));
  
positive.code: 
  
  void newGame() {
    print("newGame triggered");
  
  
    CanvasElement element = querySelector(".game-element");
    gameLoop = new GameLoopHtml(element);
    canvas = element.context2D;
  
negative.code:     pts.text = "Points: ${points}";
    }
  
  
    List<Coord> getCoords() {
      return coords;
    }
  
    // Detect if we're outside the canvas.
    bool isOnCanvas(Coord coord) {
  