@Test
 public void newBallIsNotInside() {
   Ball ball = new DummyPhysics().createBall();
   Goalpost gp = new DummyPhysics().createGoalpost(Direction.NORTH);
   assertFalse(gp.isInside(ball));
 }
 @Test
 public void createGoalpost_South() {
   Goalpost gp = new DummyPhysics().createGoalpost(Direction.SOUTH);
   assertEquals(gp.getFacing(), Direction.SOUTH);
 }