// test with a large, not-subsized Spliterator
    List<Integer> list =
        IntStream.rangeClosed(0, 10000).boxed().collect(Collectors.toCollection(LinkedList::new));
    assertThat(findLast(list.stream())).hasValue(10000);

    // no way to find out the stream is empty without walking its spliterator
    assertThat(findLast(list.stream().filter(i -> i < 0))).isEmpty();
  }

  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();

      public int characteristics() {
        return fromSpliterator.characteristics()
            & ~(Spliterator.DISTINCT | Spliterator.NONNULL | Spliterator.SORTED);
      }
    };
  }

  /** Returns a {@code Spliterator} filtered by the specified predicate. */
  static <T extends @Nullable Object> Spliterator<T> filter(
      Spliterator<T> fromSpliterator, Predicate<? super T> predicate) {
    checkNotNull(fromSpliterator);

     * 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 int size() {
    return map.size();
  }

  @Override
  public UnmodifiableIterator<K> iterator() {
    return map.keyIterator();
  }

  @Override
  public Spliterator<K> spliterator() {
    return map.keySpliterator();
  }

  @Override
  public boolean contains(@CheckForNull Object object) {
    return map.containsKey(object);
  }

  @Override
  K get(int index) {

  }

  @Override
  Set<Entry<K, V>> createEntrySet() {
    @WeakOuter
    class EntrySetImpl extends EntrySetView {
      @Override
      public Spliterator<Entry<K, V>> spliterator() {
        return Spliterators.spliterator(this, Spliterator.ORDERED | Spliterator.DISTINCT);
      }
    }
    return new EntrySetImpl();
  }

  @Override
  Set<K> createKeySet() {
    @WeakOuter

    return false;
  }

  @Override
  public UnmodifiableIterator<E> iterator() {
    return Iterators.unmodifiableIterator(delegate.iterator());
  }

  @Override
  public Spliterator<E> spliterator() {
    return delegate.spliterator();
  }

  @Override
  public void forEach(Consumer<? super E> action) {
    delegate.forEach(action);
  }

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

                    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 <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;