@CollectionFeature.Require(value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {
    E[] array = createArrayWithNullElement();
    collection = getSubjectGenerator().create(array);
    assertTrue("add(nullPresent) should return true", getList().add(null));

    List<E> expected = copyToList(array);
    expected.add(null);
    expectContents(expected);
  }

  /**

    if (parentBuilder.getFeatures().contains(SERIALIZABLE)) {
      derivedSuites.add(
          CollectionTestSuiteBuilder.using(
                  new ReserializedCollectionGenerator<E>(parentBuilder.getSubjectGenerator()))
              .named(getName() + " reserialized")
              .withFeatures(computeReserializedCollectionFeatures(parentBuilder.getFeatures()))
              .suppressing(parentBuilder.getSuppressedTests())

          parentBuilder,
      Bound from,
      Bound to) {
    TestSortedSetGenerator<E> delegate =
        (TestSortedSetGenerator<E>) parentBuilder.getSubjectGenerator().getInnerGenerator();

    List<Feature<?>> features = new ArrayList<>(parentBuilder.getFeatures());
    Set<Method> suppressing = new HashSet<>(parentBuilder.getSuppressedTests());

  @ListFeature.Require(SUPPORTS_SET)
  public void testSet_replacingNull() {
    E[] elements = createSamplesArray();
    int i = aValidIndex();
    elements[i] = null;
    collection = getSubjectGenerator().create(elements);

    doTestSet(e3());
  }

  private void doTestSet(E newValue) {
    int index = aValidIndex();
    E initialValue = getList().get(index);
    assertEquals(

  @Override
  public void setUp() throws Exception {
    super.setUp();
    sortedMultiset = (SortedMultiset<E>) getMultiset();
    entries =
        copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
    sort(entries, sortedMultiset.comparator());

    // some tests assume SEVERAL == 3
    if (entries.size() >= 1) {

  @SuppressWarnings("UndefinedEquals")
  private void assertCleared() {
    assertEquals(0, multimap().size());
    assertEmpty(multimap());
    assertEquals(multimap(), getSubjectGenerator().create());
    assertEmpty(multimap().entries());
    assertEmpty(multimap().asMap());
    assertEmpty(multimap().keySet());
    assertEmpty(multimap().keys());
    assertEmpty(multimap().values());

          parentBuilder,
      Bound from,
      Bound to) {
    TestSortedMapGenerator<K, V> delegate =
        (TestSortedMapGenerator<K, V>) parentBuilder.getSubjectGenerator().getInnerGenerator();

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

    return newBuilderUsing(delegate, to, from)

          Platform.format(
              "%s [collection size: %s]", name, collectionSize.toString().toLowerCase());
      OneSizeGenerator<T, E> oneSizeGenerator =
          new OneSizeGenerator<>(getSubjectGenerator(), (CollectionSize) collectionSize);
      Set<Feature<?>> oneSizeFeatures = copyToSet(features);
      oneSizeFeatures.add(collectionSize);
      Set<Method> oneSizeSuppressedTests = getSuppressedTests();

    expectUnchanged();
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_nullPresent() {
    collection = getSubjectGenerator().create(createArrayWithNullElement());

    int initialSize = collection.size();
    assertTrue("remove(null) should return true", collection.remove(null));
    assertEquals(

   */
  @SuppressWarnings("UndefinedEquals")
  public void testRetainAllPropagatesToMultimap() {
    multimap().entries().retainAll(singleton(mapEntry(k0(), v0())));
    assertEquals(getSubjectGenerator().create(mapEntry(k0(), v0())), multimap());
    assertEquals(1, multimap().size());
    assertTrue(multimap().containsEntry(k0(), v0()));
  }

  @CollectionSize.Require(ONE)