@Override
  public int size()
  {
    return _size;
  }
@Test
  public void testRemoveLast()
  {
    List<Integer> control = new ArrayList<>(Arrays.asList(1, 2, 3));
    LinkedDeque<Integer> q = new LinkedDeque<>(control);

    Assert.assertEquals(q.removeLast(), control.remove(control.size() - 1));
    Assert.assertEquals(q, control);
  }