TestSortedSetGenerator<E> delegate, Bound to, Bound from) {
    return using(new NavigableSetSubsetTestSetGenerator<E>(delegate, to, from));
  }

  /** Create a suite whose maps are descending views of other maps. */
  private TestSuite createDescendingSuite(
      FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<E>, E>>
          parentBuilder) {

    List<Feature<?>> features = new ArrayList<>();
    features.add(NoRecurse.DESCENDING);
    features.addAll(parentBuilder.getFeatures());

    return subSuiteUsing(new DescendingTestMapGenerator<K, V>(delegate))
        .named(parentBuilder.getName() + " descending")
        .withFeatures(features)
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  }

  @CollectionSize.Require(SEVERAL)
  public void testDescendingNavigation() {
    List<E> descending = new ArrayList<>();
    for (Iterator<E> i = navigableSet.descendingIterator(); i.hasNext(); ) {
      descending.add(i.next());
    }
    Collections.reverse(descending);
    assertEquals(values, descending);
  }

  public void testEmptySubSet() {

    List<Feature<?>> features = new ArrayList<>();
    features.add(NoRecurse.DESCENDING);
    features.addAll(parentBuilder.getFeatures());

    return subSuiteUsing(new DescendingTestMapGenerator<K, V>(delegate))
        .named(parentBuilder.getName() + " descending")
        .withFeatures(features)
        .suppressing(parentBuilder.getSuppressedTests())
        .createTestSuite();
  }

  }

  @CollectionSize.Require(SEVERAL)
  public void testDescendingNavigation() {
    List<E> descending = new ArrayList<>();
    for (Iterator<E> i = navigableSet.descendingIterator(); i.hasNext(); ) {
      descending.add(i.next());
    }
    Collections.reverse(descending);
    assertEquals(values, descending);
  }

  public void testEmptySubSet() {

   */
  enum NoRecurse implements Feature<@Nullable Void> {
    SUBMAP,
    DESCENDING;

    @Override
    public Set<Feature<? super @Nullable Void>> getImpliedFeatures() {
      return emptySet();
    }
  }

  /**
   * Creates a suite whose map has some elements filtered out of view.
   *
   * <p>Because the map may be ascending or descending, this test must derive the relative order of

   */
  enum NoRecurse implements Feature<@Nullable Void> {
    SUBMAP,
    DESCENDING;

    @Override
    public Set<Feature<? super @Nullable Void>> getImpliedFeatures() {
      return emptySet();
    }
  }

  /**
   * Creates a suite whose map has some elements filtered out of view.
   *
   * <p>Because the map may be ascending or descending, this test must derive the relative order of

  }

  /**
   * To avoid infinite recursion, test suites with these marker features won't have derived suites
   * created for them.
   */
  enum NoRecurse implements Feature<Void> {
    SUBMULTISET,
    DESCENDING;

    @Override
    public Set<Feature<? super Void>> getImpliedFeatures() {
      return emptySet();
    }
  }

  /** Two bounds (from and to) define how to build a subMultiset. */
  enum Bound {

  }

  @CollectionSize.Require(SEVERAL)
  public void testDescendingNavigation() {
    List<Entry<K, V>> descending = new ArrayList<>(navigableMap.descendingMap().entrySet());
    Collections.reverse(descending);
    assertEquals(entries, descending);
  }

  @CollectionSize.Require(absent = ZERO)
  public void testHeadMapExclusive() {

  public void testDescendingNavigation() {
    List<Entry<E>> ascending = new ArrayList<>();
    Iterators.addAll(ascending, sortedMultiset.entrySet().iterator());
    List<Entry<E>> descending = new ArrayList<>();
    Iterators.addAll(descending, sortedMultiset.descendingMultiset().entrySet().iterator());
    Collections.reverse(descending);
    assertEquals(ascending, descending);
  }