anchor.diff:  
       game.keyboard.onKeyDown.where(((e) => e.keyCode == Keys.SPACE)).listen((e) {
         ballbody.speed.setValues(100.0, 200.0);
  +      message.runAction(new FadeOut(1));
       });
     });
   
  
positive.code:     wallsCollision.collider2 = world.collider;
      wallsCollision.onCollision.listen(bounce);
      wallsCollision.onCollision.listen((event) {
        if (event.delta.x != 0.0) {
          ballbody.position.setValues(400.0, 200.0);
          ballbody.speed.setValues(0.0, 0.0);
        }
  
negative.code:     });
  
      var paddle2wallCollision = new StaticBodyOutOfBoundsCollisionCheck()
        ..collider1 = body2.collider
        ..collider2 = world.collider;
  
  