}

  private final Map<Class<? extends @NonNull B>, B> delegate;

  private MutableClassToInstanceMap(Map<Class<? extends @NonNull B>, B> delegate) {
    this.delegate = checkNotNull(delegate);
  }

  @Override
  protected Map<Class<? extends @NonNull B>, B> delegate() {
    return delegate;
  }

  /**

@ElementTypesAreNonnullByDefault
abstract class ForwardingLock implements Lock {
  abstract Lock delegate();

  @Override
  public void lock() {
    delegate().lock();
  }

  @Override
  public void lockInterruptibly() throws InterruptedException {
    delegate().lockInterruptibly();
  }

  @Override
  public boolean tryLock() {
    return delegate().tryLock();
  }

  @Override

  RegularImmutableAsList(ImmutableCollection<E> delegate, ImmutableList<? extends E> delegateList) {
    this.delegate = delegate;
    this.delegateList = delegateList;
  }

  RegularImmutableAsList(ImmutableCollection<E> delegate, Object[] array) {
    this(delegate, ImmutableList.<E>asImmutableList(array));
  }

  @Override
  ImmutableCollection<E> delegateCollection() {
    return delegate;
  }

  @Override
  public int size() {
    Set<E> delegate = delegateOrNull();
    return (delegate != null) ? delegate.size() : size;
  }

  @Override
  public boolean isEmpty() {
    return size() == 0;
  }

  @Override
  public @Nullable Object[] toArray() {
    if (needsAllocArrays()) {
      return new Object[0];
    }
    Set<E> delegate = delegateOrNull();

  @Override
  protected abstract BlockingQueue<E> delegate();

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c, int maxElements) {
    return delegate().drainTo(c, maxElements);
  }

  @CanIgnoreReturnValue
  @Override
  public int drainTo(Collection<? super E> c) {
    return delegate().drainTo(c);
  }

  @CanIgnoreReturnValue // TODO(kak): consider removing this

        super(original);
        this.in = new Reader() {
            Reader delegate = null;

            @Override
            public int read(char[] cbuf, int off, int len) throws IOException {
                if (delegate == null) {
                    delegate = transform(original);
                }
                return delegate.read(cbuf, off, len);
            }

            @Override

          insert(newEntry, delegate);
          delegate.prevInKeyInsertionOrder = null;
          delegate.nextInKeyInsertionOrder = null;
          expectedModCount = modCount;
          if (toRemove == delegate) {
            toRemove = newEntry;
          }
          delegate = newEntry;
          return oldValue;
        }
      }
    };
  }

  @Override

  /** Constructor for use by subclasses. */
  protected ForwardingSortedMultiset() {}

  @Override
  protected abstract SortedMultiset<E> delegate();

  @Override
  public NavigableSet<E> elementSet() {
    return delegate().elementSet();
  }

  /**
   * A sensible implementation of {@link SortedMultiset#elementSet} in terms of the following

  @Override
  protected abstract ListIterator<E> delegate();

  @Override
  public void add(@ParametricNullness E element) {
    delegate().add(element);
  }

  @Override
  public boolean hasPrevious() {
    return delegate().hasPrevious();
  }

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

  @CanIgnoreReturnValue
  @Override

@GwtCompatible(serializable = true)
@ElementTypesAreNonnullByDefault
final class JdkBackedImmutableSet<E> extends IndexedImmutableSet<E> {
  private final Set<?> delegate;
  private final ImmutableList<E> delegateList;

  JdkBackedImmutableSet(Set<?> delegate, ImmutableList<E> delegateList) {
    this.delegate = delegate;
    this.delegateList = delegateList;
  }

  @Override
  E get(int index) {
    return delegateList.get(index);
  }