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

    assertTrue(oriPrev == Orientation.WEST);
  }
  @Test
  public void orientationValidNextTest2() {
    Orientation ori = Orientation.SOUTH;
    Orientation oriNext = Orientation.getNext(ori);

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

    assertTrue(oriPrev == Orientation.NORTH);
  }
  @Test
  public void orientationValidNextTest1() {
    Orientation ori = Orientation.EAST;
    Orientation oriNext = Orientation.getNext(ori);

    assertTrue(oriNext == Orientation.SOUTH);
  }