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", ""}),

public abstract class ImmutableCollection<E> extends AbstractCollection<E> implements Serializable {
  static final int SPLITERATOR_CHARACTERISTICS =
      Spliterator.IMMUTABLE | Spliterator.NONNULL | Spliterator.ORDERED;

  ImmutableCollection() {}

  @Override
  public abstract UnmodifiableIterator<E> iterator();

  @Override
  public boolean contains(@Nullable Object object) {

    Spliterator<A> splitrA = streamA.spliterator();
    Spliterator<B> splitrB = streamB.spliterator();
    int characteristics =
        splitrA.characteristics()
            & splitrB.characteristics()
            & (Spliterator.SIZED | Spliterator.ORDERED);
    Iterator<A> itrA = Spliterators.iterator(splitrA);
    Iterator<B> itrB = Spliterators.iterator(splitrB);
    return StreamSupport.stream(

  private abstract static class GeneralSpliterator<E extends @Nullable Object> {
    final Spliterator<E> spliterator;

    GeneralSpliterator(Spliterator<E> spliterator) {
      this.spliterator = checkNotNull(spliterator);
    }

    abstract void forEachRemaining(Consumer<? super E> action);

    abstract boolean tryAdvance(Consumer<? super E> action);

     * they were given.
     */
    void inOrder();
  }

  private abstract static class GeneralSpliterator<E extends @Nullable Object> {
    final Spliterator<E> spliterator;

    GeneralSpliterator(Spliterator<E> spliterator) {
      this.spliterator = checkNotNull(spliterator);
    }

    abstract void forEachRemaining(Consumer<? super E> action);

    abstract boolean tryAdvance(Consumer<? super E> action);

    }

    @Override
    public Spliterator<K> spliterator() {
      if (needsAllocArrays()) {
        return Spliterators.spliterator(new Object[0], Spliterator.DISTINCT | Spliterator.ORDERED);
      }
      Map<K, V> delegate = delegateOrNull();
      return (delegate != null)
          ? delegate.keySet().spliterator()
          : Spliterators.spliterator(

   * accessor method (under -target 8) that would lack the Android flavor's @IgnoreJRERequirement.
   */
  Spliterator.OfLong spliterator() {
    return Spliterators.spliterator(array, start, end, Spliterator.IMMUTABLE | Spliterator.ORDERED);
  }

  /**
   * Returns an immutable <i>view</i> of this array's values as a {@code List}; note that {@code

  /*
   * We expect SIZED (and SUBSIZED, if applicable) to be added by the spliterator factory methods.
   * These are properties of the collection as a whole; SIZED and SUBSIZED are more properties of
   * the spliterator implementation.
   */
  static final int SPLITERATOR_CHARACTERISTICS =
      Spliterator.IMMUTABLE | Spliterator.NONNULL | Spliterator.ORDERED;

  ImmutableCollection() {}

   * accessor method (under -target 8) that would lack the Android flavor's @IgnoreJRERequirement.
   */
  Spliterator.OfInt spliterator() {
    return Spliterators.spliterator(array, start, end, Spliterator.IMMUTABLE | Spliterator.ORDERED);
  }

  /**
   * Returns an immutable <i>view</i> of this array's values as a {@code List}; note that {@code