public class PointMain {
  public static void main(String args[]) {
    Point p = new Point(10,20);

    System.out.println("before: " + p);

    p.x += 5;
    p.y += 5;
        
    p.move(5, 5);

    System.out.println("after: " + p);
    
    /* we didn't write this: */
    // move(p, 5, 5);

    Point p2 = new Point(5, 5);
    p2.move(-1, 100);

    // p.move(p2);

    System.out.println("after: " + p2);
  }
}