@Override
    public List<Integer> order(List<Integer> insertionOrder) {
      return insertionOrder;
    }
  }

  public static class SampleIntegers extends SampleElements<Integer> {
    public SampleIntegers() {
      super((int) 0, (int) 1, (int) 2, (int) 3, (int) 4);
    }
  }