private E a;
  private E b;
  private E c;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableSet = (NavigableSet<E>) getSet();
    values =
        Helpers.copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    Collections.sort(values, navigableSet.comparator());

   * in the list under test matches what is expected.
   */
  @Override
  protected void expectContents(Collection<E> expectedCollection) {
    List<E> expectedList = Helpers.copyToList(expectedCollection);
    // Avoid expectEquals() here to delay reason manufacture until necessary.
    if (getList().size() != expectedList.size()) {
      fail("size mismatch: " + reportContext(expectedList));
    }

  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(value = KNOWN_ORDER, absent = NON_STANDARD_TOSTRING)
  public void testToString_sizeSeveral() {
    String expected = Helpers.copyToList(getOrderedElements()).toString();
    assertEquals("collection.toString() incorrect", expected, collection.toString());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)

  }

  // Clone of Lists.newArrayList
  public static <E extends @Nullable Object> List<E> copyToList(Iterable<? extends E> elements) {
    List<E> list = new ArrayList<>();
    addAll(list, elements);
    return list;
  }

  public static <E extends @Nullable Object> List<E> copyToList(E[] elements) {
    return copyToList(Arrays.asList(elements));
  }

  // Clone of Sets.newLinkedHashSet

    sortedMultiset.tailMultiset(b.getElement(), CLOSED).clear();
    assertEquals(expected, copyToList(sortedMultiset.entrySet()));
  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  public void testClearTailClosedEntrySet() {
    List<Entry<E>> expected =
        copyToList(sortedMultiset.headMultiset(b.getElement(), OPEN).entrySet());

  }

  @SuppressWarnings("rawtypes") // class literals
  @Override
  protected List<Class<? extends AbstractTester>> getTesters() {
    List<Class<? extends AbstractTester>> testers = Helpers.copyToList(super.getTesters());

    testers.add(CollectionSerializationEqualTester.class);
    testers.add(SetAddAllTester.class);
    testers.add(SetAddTester.class);
    testers.add(SetCreationTester.class);

  private Entry<K, V> b;
  private Entry<K, V> c;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableMap = (NavigableMap<K, V>) getMap();
    entries =
        Helpers.copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    Collections.sort(entries, Helpers.<K, V>entryComparator(navigableMap.comparator()));

    List<Class<? extends AbstractTester>> testers = Helpers.copyToList(super.getTesters());
    testers.add(SortedSetNavigationTester.class);
    return testers;
  }

  @Override
  public TestSuite createTestSuite() {
    if (!getFeatures().contains(CollectionFeature.KNOWN_ORDER)) {
      List<Feature<?>> features = Helpers.copyToList(getFeatures());
      features.add(CollectionFeature.KNOWN_ORDER);

  }

  @SuppressWarnings("rawtypes") // class literals
  @Override
  protected List<Class<? extends AbstractTester>> getTesters() {
    List<Class<? extends AbstractTester>> testers = Helpers.copyToList(super.getTesters());

    testers.add(CollectionSerializationEqualTester.class);
    testers.add(ListAddAllAtIndexTester.class);
    testers.add(ListAddAllTester.class);
    testers.add(ListAddAtIndexTester.class);

    List<E> expected = Helpers.copyToList(getSampleElements());
    expected.addAll(Arrays.asList(elements));
    expectContents(expected);
  }

  protected final void expectAdded(int index, E... elements) {
    expectAdded(index, Arrays.asList(elements));
  }

  protected final void expectAdded(int index, Collection<E> elements) {
    List<E> expected = Helpers.copyToList(getSampleElements());