anchor.diff:      position = new Vector2(x, y);
       size = new Vector2(width, height);
     }
  +
  +  void update(num dt) {
  +
  +  }
   }
  
positive.code: 
  part of cocos;
  
  class PhysicsComponent {
    GameNode node;
    World world;
  
negative.code:     node.position.y += speed.y * dt;
      speed.x += acceleration.x * dt;
      speed.y += acceleration.y * dt;
    }
  }
  
  