}

                  @Override
                  public List<String> order(List<String> insertionOrder) {
                    return Ordering.natural().sortedCopy(insertionOrder);
                  }
                })
            .named("ForwardingSortedMultiset with standard impls")
            .withFeatures(
                CollectionSize.ANY,

    sort(insertionOrder, entryComparator(keyComparator));
    return insertionOrder;
  }

  /**
   * Compares strings in natural order except that null comes immediately before a given value. This
   * works better than Ordering.natural().nullsFirst() because, if null comes before all other
   * values, it lies outside the submap/submultiset ranges we test, and the variety of tests that

        builder.put(elements[i], i);
      }
      return builder.build().keySet().asList();
    }

    @Override
    public List<String> order(List<String> insertionOrder) {
      return Ordering.<String>natural().sortedCopy(insertionOrder);
    }
  }

  public static class ImmutableSortedMapValueListGenerator extends TestStringListGenerator {
    @Override
    protected List<String> create(String[] elements) {

   */
  @Override
  public Map<K, Collection<V>> asMap() {
    return super.asMap();
  }

  /**
   * {@inheritDoc}
   *
   * <p>Consequently, the values do not follow their natural ordering or the ordering of the value
   * comparator.
   */
  @Override
  public Collection<V> values() {
    return super.values();
  }

    throw new InvalidObjectException("Use SerializedForm");
  }

  @GwtIncompatible // NavigableSet
  @Override
  ImmutableSortedSet<C> createDescendingSet() {
    return ImmutableSortedSet.emptySet(Ordering.<C>natural().reverse());
  }

                    }
                    return new StandardImplForwardingSortedMap<>(map);
                  }
                })
            .named(
                "ForwardingSortedMap[SafeTreeMap] with natural comparator and "
                    + "standard implementations")
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.KNOWN_ORDER,

    @Override
    public Integer[] createArray(int length) {
      return new Integer[length];
    }

    @Override
    public Iterable<Integer> order(List<Integer> insertionOrder) {
      return Ordering.natural().sortedCopy(insertionOrder);
    }

    @Override
    public Set<Integer> create(Object... elements) {
      ImmutableRangeSet.Builder<Integer> builder = ImmutableRangeSet.builder();
      for (Object o : elements) {

   */
  @Override
  Map<K, Collection<V>> asMap();

  /**
   * Returns the comparator that orders the multimap values, with {@code null} indicating that
   * natural ordering is used.
   */
  @Nullable Comparator<? super V> valueComparator();

      Iterable<Iterable<Integer>> iterables, Iterable<Integer> unsortedExpected) {
    Iterable<Integer> expected = Ordering.<Integer>natural().sortedCopy(unsortedExpected);

    Iterable<Integer> mergedIterator = mergeSorted(iterables, Ordering.natural());

    assertEquals(Lists.newLinkedList(expected), Lists.newLinkedList(mergedIterator));
  }

  }

  public void testOrderedPermutationSetRepeatedElements() {
    List<Integer> list = newArrayList(1, 1, 2, 2);
    Iterator<List<Integer>> permutations =
        Collections2.orderedPermutations(list, Ordering.natural()).iterator();

    assertNextPermutation(newArrayList(1, 1, 2, 2), permutations);
    assertNextPermutation(newArrayList(1, 2, 1, 2), permutations);
    assertNextPermutation(newArrayList(1, 2, 2, 1), permutations);