@Test
  public void orientationValidPrevTest2() {
    Orientation ori = Orientation.NORTH;
    Orientation oriPrev = Orientation.getPrev(ori);

    assertTrue(oriPrev == Orientation.WEST);
  }
  @Test
  public void orientationValidPrevTest1() {
    Orientation ori = Orientation.EAST;
    Orientation oriPrev = Orientation.getPrev(ori);

    assertTrue(oriPrev == Orientation.NORTH);
  }