assertTransformModifiable(list);
  }

  private static void assertTransformModifiable(List<String> list) {
    try {
      list.add("5");
      fail("transformed list is addable");
    } catch (UnsupportedOperationException expected) {
    }
    list.remove(0);
    assertEquals(asList("2", "3", "4"), list);
    list.remove("3");
    assertEquals(asList("2", "4"), list);
    try {

      super.addAll(elements);
      return this;
    }

    @CanIgnoreReturnValue
    Builder<E> combine(Builder<E> builder) {
      contents.addAll(builder.contents);
      return this;
    }

    @Override
    public ImmutableSet<E> build() {
      return copyOf(contents.iterator());
    }
  }

  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()));

        UnsupportedOperationException.class, () -> getList().addAll(0, MinimalCollection.of(e0())));
    expectUnchanged();
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAllAtIndex_supportedSomePresent() {
    assertTrue(
        "addAll(n, allPresent) should return true",
        getList().addAll(0, MinimalCollection.of(e0(), e3())));
    expectAdded(0, e0(), e3());

    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));

        assertThat(ArrayUtil.addAll((Object[]) null, (Object[]) null), is(nullValue()));
        assertThat(ArrayUtil.addAll(null, emptyArray).length, is(0));
        assertThat(ArrayUtil.addAll(emptyArray, null), is(sameInstance(emptyArray)));
        assertThat(ArrayUtil.addAll(emptyArray, null), is(sameInstance(emptyArray)));
        assertThat(ArrayUtil.addAll(emptyArray, emptyArray), is(sameInstance(emptyArray)));

  public void addAll(LongStream values) {
    addAll(values.collect(StatsAccumulator::new, StatsAccumulator::add, StatsAccumulator::addAll));
  }

  /**
   * Adds the given statistics to the dataset, as if the individual values used to compute the
   * statistics had been added directly.
   */
  public void addAll(Stats values) {
    if (values.count() == 0) {
      return;

        UnsupportedOperationException.class, () -> getList().addAll(0, MinimalCollection.of(e0())));
    expectUnchanged();
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAllAtIndex_supportedSomePresent() {
    assertTrue(
        "addAll(n, allPresent) should return true",
        getList().addAll(0, MinimalCollection.of(e0(), e3())));
    expectAdded(0, e0(), e3());

      }
      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

    assertEquals(HashMultiset.create(asList("a", "b", "b", "b", "c")), multiset);
  }

  public void testBuilderAddAllIterator() {
    Iterator<String> iterator = asList("a", "b", "a", "c").iterator();
    ImmutableMultiset<String> multiset =
        new ImmutableMultiset.Builder<String>().addAll(iterator).build();
    assertEquals(HashMultiset.create(asList("a", "b", "a", "c")), multiset);
  }