@Test
  public void Add_Two_RoundBinding() {
    // arrange
    Route route1 = new Route("", 1);
    Route route2 = new Route("", 2);
    Route result = null;

    // act
    _routes.add(route1);
    _routes.add(route2);

    // assert
    result = _routes.get(route1);
    assertEquals(route1, result);
    result = _routes.get(route2);
    assertEquals(route2, result);
    result = _routes.getNext(route1);
    assertEquals(route2, result);
    result = _routes.getNext(result);
    assertEquals(route1, result);
    result = _routes.getPrevious(route2);
    assertEquals(route1, result);
    result = _routes.getPrevious(result);
    assertEquals(route2, result);
  }
  @Test
  public void AddWithIndex_One_GotItInAnyCase() {
    // arrange
    Route route = new Route("", 1);
    Route result = null;

    // act
    _routes.add(route, 1);

    // assert
    result = _routes.get(route);
    assertEquals(route, result);
    result = _routes.get(1);
    assertEquals(route, result);
    result = _routes.get(2);
    assertEquals(route, result);
    result = _routes.get(3);
    assertEquals(route, result);
    result = _routes.getNext(route);
    assertEquals(route, result);
    result = _routes.getPrevious(route);
    assertEquals(route, result);
  }