@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;

  public void testListeningDecorator_noWrapExecuteTask() {
    ExecutorService delegate = mock(ExecutorService.class);
    ListeningExecutorService service = listeningDecorator(delegate);
    Runnable task =
        new Runnable() {
          @Override
          public void run() {}
        };
    service.execute(task);
    verify(delegate).execute(task);
  }

  public void testListeningDecorator_noWrapExecuteTask() {
    ExecutorService delegate = mock(ExecutorService.class);
    ListeningExecutorService service = listeningDecorator(delegate);
    Runnable task =
        new Runnable() {
          @Override
          public void run() {}
        };
    service.execute(task);
    verify(delegate).execute(task);
  }

        .addEqualityGroup(map2, wrap(map2))
        .testEquals();
  }

  private static <K, V> NavigableMap<K, V> wrap(NavigableMap<K, V> delegate) {
    return new ForwardingNavigableMap<K, V>() {
      @Override
      protected NavigableMap<K, V> delegate() {
        return delegate;
      }
    };
  }

    private final NavigableMap<K, ? extends V> delegate;

    UnmodifiableNavigableMap(NavigableMap<K, ? extends V> delegate) {
      this.delegate = delegate;
    }

    UnmodifiableNavigableMap(
        NavigableMap<K, ? extends V> delegate, UnmodifiableNavigableMap<K, V> descendingMap) {
      this.delegate = delegate;
      this.descendingMap = descendingMap;
    }

    @Override

  @Override
  Set<E> createElementSet() {
    Set<E> delegate = countMap.keySet();
    return new ForwardingSet<E>() {
      @Override
      protected Set<E> delegate() {
        return delegate;
      }

      @Override
      public boolean contains(@Nullable Object object) {
        return object != null && Collections2.safeContains(delegate, object);
      }

      @Override

  /** Proxy to throw a {@link RuntimeException} out of the {@link #get()} method. */
  public static class BadFuture extends SimpleForwardingListenableFuture<Integer> {
    protected BadFuture(ListenableFuture<Integer> delegate) {
      super(delegate);
    }

    @Override
    public Integer get() {
      throw new BadFutureRuntimeException();
    }
  }

  /** Proxy to throw a {@link RuntimeException} out of the {@link #get()} method. */
  public static class BadFuture extends SimpleForwardingListenableFuture<Integer> {
    protected BadFuture(ListenableFuture<Integer> delegate) {
      super(delegate);
    }

    @Override
    public Integer get() {
      throw new BadFutureRuntimeException();
    }
  }

   */
  private static final class JdkBackedSetBuilderImpl<E> extends SetBuilderImpl<E> {
    private final Set<Object> delegate;

    JdkBackedSetBuilderImpl(SetBuilderImpl<E> toCopy) {
      super(toCopy); // initializes dedupedElements and distinct
      delegate = Sets.newHashSetWithExpectedSize(distinct);
      for (int i = 0; i < distinct; i++) {
        /*

        private volatile Map<K, V> delegate;

        LazyMap(Supplier<Map<K, V>> supplier) {
            this.supplier = supplier;
        }

        @Override
        public Set<Entry<K, V>> entrySet() {
            if (delegate == null) {
                synchronized (this) {
                    if (delegate == null) {
                        delegate = supplier.get();
                    }