/** Test the set active powerups method. */
 @Test
 public final void testSetActivePowerUps() {
   ArrayList<PowerUp> powerups = new ArrayList<PowerUp>();
   PowerUp powerup = new ShootPowerUp(player);
   powerups.add(powerup);
   player.setActivePowerUps(powerups);
   assertEquals(player.getActivePowerUps(), powerups);
 }