assertFalse("addAll(n, nothing) should return false", getList().addAll(0, emptyCollection()));
    expectUnchanged();
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  public void testAddAllAtIndex_unsupportedNothing() {
    try {
      assertFalse(
          "addAll(n, nothing) should return false or throw",
          getList().addAll(0, emptyCollection()));

  public void testAddAll_supportedNothing() {
    assertFalse("addAll(nothing) should return false", collection.addAll(emptyCollection()));
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddAll_unsupportedNothing() {
    try {
      assertFalse(
          "addAll(nothing) should return false or throw", collection.addAll(emptyCollection()));

    oneValueAccumulatorByAddAllEmptyStats.addAll(Stats.of());

    twoValuesAccumulator = new StatsAccumulator();
    twoValuesAccumulator.addAll(TWO_VALUES);

    twoValuesAccumulatorByAddAllStats = new StatsAccumulator();
    twoValuesAccumulatorByAddAllStats.addAll(Stats.of(ONE_VALUE));
    twoValuesAccumulatorByAddAllStats.addAll(Stats.of(OTHER_ONE_VALUE));

    assertTrue(
        "add(somePresent) should return true", getSet().addAll(MinimalCollection.of(e3(), e0())));
    expectAdded(e3());
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_withDuplicates() {
    MinimalCollection<E> elementsToAdd = MinimalCollection.of(e3(), e4(), e3(), e4());
    assertTrue("add(hasDuplicates) should return true", getSet().addAll(elementsToAdd));
    expectAdded(e3(), e4());
  }

  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_emptySet() {
    assertFalse(getMultiset().addAll(Collections.<E>emptySet()));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_emptyMultiset() {
    assertFalse(getMultiset().addAll(getSubjectGenerator().create()));
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_ADD)

 * methods of the delegate. For example, overriding {@link #add} alone <b>will not</b> change the
 * behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code addAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardAddAll} method.
 *

      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsAll(collection);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.addAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      assertTrue(Thread.holdsLock(mutex));

        ImmutableSortedMultiset.<String>naturalOrder().addAll(a).addAll(b).build();
    assertEquals(HashMultiset.create(asList("a", "b", "b", "b", "c")), multiset);
  }

  public void testBuilderAddAllIterator() {
    Iterator<String> iterator = asList("a", "b", "a", "c").iterator();
    ImmutableSortedMultiset<String> multiset =
        ImmutableSortedMultiset.<String>naturalOrder().addAll(iterator).build();

      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterable<? extends E> elements) {
      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterator<? extends E> elements) {
      checkNotNull(elements); // for GWT

        ImmutableSortedMultiset.<String>naturalOrder().addAll(a).addAll(b).build();
    assertEquals(HashMultiset.create(asList("a", "b", "b", "b", "c")), multiset);
  }

  public void testBuilderAddAllIterator() {
    Iterator<String> iterator = asList("a", "b", "a", "c").iterator();
    ImmutableSortedMultiset<String> multiset =
        ImmutableSortedMultiset.<String>naturalOrder().addAll(iterator).build();