assertNextPermutation(newArrayList(2, 3, 1), permutations);
    assertNextPermutation(newArrayList(2, 1, 3), permutations);
    assertNoMorePermutations(permutations);
  }

  public void testPermutationSetThreeElementsOutOfOrder() {
    Iterator<List<Integer>> permutations =
        Collections2.permutations(newArrayList(3, 2, 1)).iterator();
    assertNextPermutation(newArrayList(3, 2, 1), permutations);