@Override
  protected abstract ConcurrentMap<K, V> delegate();

  @CanIgnoreReturnValue
  @Override
  @CheckForNull
  public V putIfAbsent(K key, V value) {
    return delegate().putIfAbsent(key, value);
  }

  @CanIgnoreReturnValue
  @Override
  public boolean remove(@CheckForNull Object key, @CheckForNull Object value) {
    return delegate().remove(key, value);
  }

  @CanIgnoreReturnValue
  @Override

        .addEqualityGroup(set2, wrap(set2))
        .testEquals();
  }

  private static <T> Multiset<T> wrap(final Multiset<T> delegate) {
    return new ForwardingMultiset<T>() {
      @Override
      protected Multiset<T> delegate() {
        return delegate;
      }
    };
  }

  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(list2, wrap(list2))
        .testEquals();
  }

  private static <T> List<T> wrap(final List<T> delegate) {
    return new ForwardingList<T>() {
      @Override
      protected List<T> delegate() {
        return delegate;
      }
    };
  }

        .addEqualityGroup(set2, wrap(set2))
        .testEquals();
  }

  private static <T> SortedMultiset<T> wrap(final SortedMultiset<T> delegate) {
    return new ForwardingSortedMultiset<T>() {
      @Override
      protected SortedMultiset<T> delegate() {
        return delegate;
      }
    };
  }

        .addEqualityGroup(list2, wrap(list2))
        .testEquals();
  }

  private static <T> List<T> wrap(final List<T> delegate) {
    return new ForwardingList<T>() {
      @Override
      protected List<T> delegate() {
        return delegate;
      }
    };
  }

    implements TestSetGenerator<E> {

  ReserializingTestSetGenerator(TestSetGenerator<E> delegate) {
    super(delegate);
  }

  public static <E> TestSetGenerator<E> newInstance(TestSetGenerator<E> delegate) {
    return new ReserializingTestSetGenerator<>(delegate);
  }

  @Override
  public Set<E> create(Object... elements) {
    return (Set<E>) super.create(elements);
  }

  @Override
  protected abstract ListeningExecutorService delegate();

  @Override
  public <T extends @Nullable Object> ListenableFuture<T> submit(Callable<T> task) {
    return delegate().submit(task);
  }

  @Override
  public ListenableFuture<?> submit(Runnable task) {
    return delegate().submit(task);
  }

  @Override

    public final Object mutex;
    private Map<K, V> delegate;

    public TestMap(Map<K, V> delegate, Object mutex) {
      checkNotNull(mutex);
      this.delegate = delegate;
      this.mutex = mutex;
    }

    @Override
    protected Map<K, V> delegate() {
      return delegate;
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));

  protected ForwardingListMultimap() {}

  @Override
  protected abstract ListMultimap<K, V> delegate();

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

  @CanIgnoreReturnValue
  @Override
  public List<V> removeAll(@CheckForNull Object key) {
    return delegate().removeAll(key);
  }

  @CanIgnoreReturnValue
  @Override