anchor.diff:      crc.fillStyle = color;
       crc.fillRect(width * x, height * y, width, height);
     }
  +
   }
   
   class Snake {
  
positive.code:   }
  
    void render(canvas) {
      coords.forEach((c) => c.render(canvas, "#FFFFFF"));
    }
  
    void increaseTail() {
  
negative.code:   void clearCanvas() {
      // final CanvasElement canvas = querySelector("#myCanvas");
      var gc = canvas.canvas.getContext('2d');
      gc.fillStyle = white_color;
      gc.fillRect(0, 0, cwidth, cheight);
    }
  
  