initCollectionWithNullElement();
    assertFalse(collection.spliterator().hasCharacteristics(Spliterator.NONNULL));
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSpliteratorNotImmutable_collectionAllowsAdd() {
    // If add is supported, verify that IMMUTABLE is not reported.
    assertFalse(collection.spliterator().hasCharacteristics(Spliterator.IMMUTABLE));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

    return new RegularImmutableSortedSet<E>(parentSubList, comparator()).asList();
  }

  @Override
  public Spliterator<E> spliterator() {
    return CollectSpliterators.indexed(
        size(),
        ImmutableList.SPLITERATOR_CHARACTERISTICS | Spliterator.SORTED | Spliterator.DISTINCT,
        delegateList()::get,
        comparator());
  }

  // redeclare to help optimizers with b/310253115

  abstract E get(int index);

  @Override
  public UnmodifiableIterator<E> iterator() {
    return asList().iterator();
  }

  @Override
  public Spliterator<E> spliterator() {
    return CollectSpliterators.indexed(size(), SPLITERATOR_CHARACTERISTICS, this::get);
  }

  @Override
  public void forEach(Consumer<? super E> consumer) {
    checkNotNull(consumer);
    int n = size();

      return Sets.equalsImpl(this, obj);
    }
  }

  abstract Iterator<Entry<K, V>> entryIterator();

  Spliterator<Entry<K, V>> entrySpliterator() {
    return Spliterators.spliterator(
        entryIterator(), size(), (this instanceof SetMultimap) ? Spliterator.DISTINCT : 0);
  }

  @LazyInit @CheckForNull private transient Set<K> keySet;

  @Override
  public Set<K> keySet() {

    initCollectionWithNullElement();
    assertFalse(collection.spliterator().hasCharacteristics(Spliterator.NONNULL));
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testSpliteratorNotImmutable_collectionAllowsAdd() {
    // If add is supported, verify that IMMUTABLE is not reported.
    assertFalse(collection.spliterator().hasCharacteristics(Spliterator.IMMUTABLE));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)

                    Spliterator.SIZED | Spliterator.DISTINCT | Spliterator.NONNULL,
                    7))
        .expect('a', 'b', 'c', 'd', 'e', 'f', 'g');
  }

  public void testFlatMap_nullStream() {
    SpliteratorTester.of(
            () ->
                CollectSpliterators.flatMap(
                    Arrays.spliterator(new String[] {"abc", "", "de", "f", "g", ""}),

  }

  @Override
  UnmodifiableIterator<K> keyIterator() {
    return Iterators.unmodifiableIterator(delegate.keySet().iterator());
  }

  @Override
  Spliterator<K> keySpliterator() {
    return delegate.keySet().spliterator();
  }

  @Override
  public int size() {
    return delegate.size();
  }

  @Override
  public boolean containsKey(@CheckForNull Object key) {

  @SuppressWarnings("unchecked")
  @Override
  public UnmodifiableIterator<E> iterator() {
    return (UnmodifiableIterator<E>) Iterators.forArray(elements);
  }

  @Override
  public Spliterator<E> spliterator() {
    return Spliterators.spliterator(elements, SPLITERATOR_CHARACTERISTICS);
  }

  @Override
  Object[] internalArray() {
    return elements;
  }

  @Override
  int internalArrayStart() {
    return 0;

  public <T extends @Nullable Object> T[] toArray(T[] a) {
    return ObjectArrays.toArrayImpl(this, a);
  }

  @Override
  public Spliterator<E> spliterator() {
    return Spliterators.spliterator(this, Spliterator.ORDERED | Spliterator.DISTINCT);
  }

  @Override
  public void clear() {
    if (needsAllocArrays()) {
      return;
    }
    this.firstEntry = ENDPOINT;

    }

    @Override
    public UnmodifiableIterator<Entry<K, V>> iterator() {
      return entries.iterator();
    }

    @Override
    public Spliterator<Entry<K, V>> spliterator() {
      return entries.spliterator();
    }

    @Override
    public void forEach(Consumer<? super Entry<K, V>> action) {
      entries.forEach(action);
    }

    @Override