private final ProgressListener progressListener;
    private final RequestBody delegate;

    public ProgressRequestBody(RequestBody delegate, ProgressListener progressListener) {
      this.delegate = delegate;
      this.progressListener = progressListener;
    }

    @Override
    public MediaType contentType() {
      return delegate.contentType();
    }

    @Override

  final transient Map<K, V> delegate;

  ForwardingImmutableMap(Map<? extends K, ? extends V> delegate) {
    this.delegate = Collections.unmodifiableMap(delegate);
  }

  @SuppressWarnings("unchecked")
  ForwardingImmutableMap(boolean throwIfDuplicateKeys, Entry<? extends K, ? extends V>... entries) {
    Map<K, V> delegate = Maps.newLinkedHashMap();

  final transient Collection<E> delegate;

  ForwardingImmutableCollection(Collection<E> delegate) {
    this.delegate = delegate;
  }

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

  @Override
  public boolean contains(@Nullable Object object) {
    return object != null && delegate.contains(object);
  }

  @Override

      return ImmutableSet.<E>of(first);
    }

    Set<E> delegate = Sets.newLinkedHashSet();
    delegate.add(checkNotNull(first));
    do {
      delegate.add(checkNotNull(elements.next()));
    } while (elements.hasNext());

    return unsafeDelegate(delegate);
  }

  // Factory methods that skips the null checks on elements, only used when

    private final TestMultisetGenerator<E> delegate;

    ForwardingTestMultisetGenerator(TestMultisetGenerator<E> delegate) {
      this.delegate = delegate;
    }

    @Override
    public SampleElements<E> samples() {
      return delegate.samples();
    }

    @Override
    public E[] createArray(int length) {
      return delegate.createArray(length);
    }

    @Override

    UnmodifiableListMultimap(ListMultimap<K, V> delegate) {
      super(delegate);
    }

    @Override
    public ListMultimap<K, V> delegate() {
      return (ListMultimap<K, V>) super.delegate();
    }

    @Override
    public List<V> get(@ParametricNullness K key) {
      return Collections.unmodifiableList(delegate().get(key));
    }

    @Override

    UnmodifiableListMultimap(ListMultimap<K, V> delegate) {
      super(delegate);
    }

    @Override
    public ListMultimap<K, V> delegate() {
      return (ListMultimap<K, V>) super.delegate();
    }

    @Override
    public List<V> get(@ParametricNullness K key) {
      return Collections.unmodifiableList(delegate().get(key));
    }

    @Override

      implements Supplier<T>, Serializable {
    final Supplier<T> delegate;

    ThreadSafeSupplier(Supplier<T> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    @ParametricNullness
    public T get() {
      synchronized (delegate) {
        return delegate.get();
      }
    }

    @Override
    public String toString() {

      insertionOrder = castOrCopyToList(delegate.order(insertionOrder));
      reverse(insertionOrder);
      return insertionOrder;
    }

    TestSortedMapGenerator<K, V> delegate() {
      return (TestSortedMapGenerator<K, V>) delegate;
    }

    @Override
    public Entry<K, V> belowSamplesLesser() {
      return delegate().aboveSamplesGreater();
    }

    @Override

    @ParametricNullness final K key;
    Collection<V> delegate;
    final @Nullable WrappedCollection ancestor;
    final @Nullable Collection<V> ancestorDelegate;

    WrappedCollection(
        @ParametricNullness K key, Collection<V> delegate, @Nullable WrappedCollection ancestor) {
      this.key = key;
      this.delegate = delegate;
      this.ancestor = ancestor;