Iterator<List<Integer>> permutations = Collections2.orderedPermutations(list).iterator();

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

  public void testOrderedPermutationSetThreeElements() {
    List<String> list = newArrayList("b", "a", "c");
    Iterator<List<String>> permutations = Collections2.orderedPermutations(list).iterator();

    Iterator<List<Integer>> permutations = Collections2.orderedPermutations(list).iterator();

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

  public void testOrderedPermutationSetThreeElements() {
    List<String> list = newArrayList("b", "a", "c");
    Iterator<List<String>> permutations = Collections2.orderedPermutations(list).iterator();

   * @throws NullPointerException if the specified iterable is null or has any null elements.
   * @since 12.0
   */
  public static <E extends Comparable<? super E>> Collection<List<E>> orderedPermutations(
      Iterable<E> elements) {
    return orderedPermutations(elements, Ordering.natural());
  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Iterable} using