expectAdded(e3());
  }

  @CollectionFeature.Require({SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  public void testOffer_nullSupported() {
    assertTrue("offer(null) should return true", getQueue().offer(null));
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
  public void testOffer_nullUnsupported() {
    try {
      getQueue().offer(null);

  private static final Feature<?>[] FOR_MAP_FEATURES_ONE = {
    CollectionSize.ONE,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE
  };

  private static final Feature<?>[] FOR_MAP_FEATURES_ANY = {
    CollectionSize.ANY,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE,

    expectAdded(e3());
  }

  @CollectionFeature.Require({SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  public void testOffer_nullSupported() {
    assertTrue("offer(null) should return true", getQueue().offer(null));
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
  public void testOffer_nullUnsupported() {
    try {
      getQueue().offer(null);

  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  public void testAddAtIndex_nullSupported() {
    getList().add(0, null);
    expectAdded(0, (E) null);
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionFeature.Require(absent = ALLOWS_NULL_VALUES)
  public void testAddAtIndex_nullUnsupported() {
    try {
      getList().add(0, null);

  private static final Feature<?>[] FOR_MAP_FEATURES_ONE = {
    CollectionSize.ONE,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE
  };

  private static final Feature<?>[] FOR_MAP_FEATURES_ANY = {
    CollectionSize.ANY,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE,

    expectUnchanged();
  }

  @CollectionFeature.Require(
      value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES},
      absent = RESTRICTS_ELEMENTS)
  public void testAdd_nullSupported() {
    assertTrue("add(null) should return true", collection.add(null));
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
  public void testAdd_nullUnsupported() {
    try {

    int size = getNumElements();

    List<V> values = Helpers.copyToList(multimap().get(k0()));

    assertTrue(multimap().put(k0(), v1()));
    assertTrue(multimap().put(k0(), v2()));

    values.add(v1());
    values.add(v2());

    assertGet(k0(), values);
    assertEquals(size + 2, multimap().size());
  }

  @MapFeature.Require({SUPPORTS_PUT, ALLOWS_NULL_VALUES})
  public void testPutNullValue_supported() {

  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(ONE)
  public void testRetainAll_nullSingletonPreviouslySingletonWithNull() {
    initCollectionWithNullElement();
    expectReturnsFalse(nullSingleton);
    expectContents(createArrayWithNullElement());
  }

  @CollectionFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = {ZERO, ONE})

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testSizeNullValue() {
    initMultimapWithNullValue();
    assertEquals(getNumElements(), multimap().size());
    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  public void testSizeNullKeyAndValue() {
    initMultimapWithNullKeyAndValue();

  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_VALUES)
  public void testSizeNullValue() {
    initMultimapWithNullValue();
    assertEquals(getNumElements(), multimap().size());
    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({ALLOWS_NULL_KEYS, ALLOWS_NULL_VALUES})
  public void testSizeNullKeyAndValue() {
    initMultimapWithNullKeyAndValue();