Set<Integer> set = Sets.newSetFromMap(new HashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);
    verifySetContents(set, SOME_COLLECTION);
  }

  @J2ktIncompatible
  @GwtIncompatible // SerializableTester
  public void testNewSetFromMapSerialization() {
    Set<Integer> set = Sets.newSetFromMap(new LinkedHashMap<Integer, Boolean>());
    set.addAll(SOME_COLLECTION);

    assertEquals(nestingDepth, Iterators.size(iterator));
  }

  public void testAddAllWithEmptyIterator() {
    List<String> alreadyThere = Lists.newArrayList("already", "there");

    boolean changed = Iterators.addAll(alreadyThere, Iterators.<String>emptyIterator());
    assertThat(alreadyThere).containsExactly("already", "there").inOrder();
    assertFalse(changed);
  }

  public void testAddAllToList() {

        .inOrder();
  }

  public void testAsMapReadsThrough() {
    Set<String> strings = Sets.newLinkedHashSet();
    Collections.addAll(strings, "one", "two", "three");
    Map<String, Integer> map = Maps.asMap(strings, LENGTH_FUNCTION);
    assertEquals(ImmutableMap.of("one", 3, "two", 3, "three", 5), map);
    assertNull(map.get("four"));

        .inOrder();
  }

  public void testAsMapReadsThrough() {
    Set<String> strings = Sets.newLinkedHashSet();
    Collections.addAll(strings, "one", "two", "three");
    Map<String, Integer> map = Maps.asMap(strings, LENGTH_FUNCTION);
    assertEquals(ImmutableMap.of("one", 3, "two", 3, "three", 5), map);
    assertNull(map.get("four"));

    @Override
    public boolean add(E e) {
      synchronized (mutex) {
        return delegate().add(e);
      }
    }

    @Override
    public boolean addAll(Collection<? extends E> c) {
      synchronized (mutex) {
        return delegate().addAll(c);
      }
    }

    @Override
    public void clear() {
      synchronized (mutex) {
        delegate().clear();
      }
    }

        set.addAll(set1);
        set.addAll(set2);
        return set;
      }

      @Override
      @SuppressWarnings({"nullness", "unchecked"}) // see supertype
      public ImmutableSet<@NonNull E> immutableCopy() {
        ImmutableSet.Builder<@NonNull E> builder =
            new ImmutableSet.Builder<@NonNull E>()
                .addAll((Iterable<@NonNull E>) set1)

  }

  private static <E> ArrayList<E> toArrayList(Collection<E> c) {
    // Avoid calling ArrayList(Collection), which may call back into toArray.
    ArrayList<E> result = new ArrayList<>(c.size());
    Iterators.addAll(result, c.iterator());
    return result;
  }

  // Serialization Support

  private static final long serialVersionUID = 5;

  Object writeReplace() {
    return new SerializationProxy<>(

    assertEquals(nestingDepth, Iterators.size(iterator));
  }

  public void testAddAllWithEmptyIterator() {
    List<String> alreadyThere = Lists.newArrayList("already", "there");

    boolean changed = Iterators.addAll(alreadyThere, Iterators.<String>emptyIterator());
    assertThat(alreadyThere).containsExactly("already", "there").inOrder();
    assertFalse(changed);
  }

  public void testAddAllToList() {

   *
   * @return {@code true} if {@code collection} was modified as a result of this operation
   */
  @CanIgnoreReturnValue
  public static <T extends @Nullable Object> boolean addAll(
      Collection<T> addTo, Iterator<? extends T> iterator) {
    checkNotNull(addTo);
    checkNotNull(iterator);
    boolean wasModified = false;
    while (iterator.hasNext()) {

   *
   * @return {@code true} if {@code collection} was modified as a result of this operation
   */
  @CanIgnoreReturnValue
  public static <T extends @Nullable Object> boolean addAll(
      Collection<T> addTo, Iterator<? extends T> iterator) {
    checkNotNull(addTo);
    checkNotNull(iterator);
    boolean wasModified = false;
    while (iterator.hasNext()) {