.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 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

        .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;
      }
    };
  }

  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);
  }

    }
    return false;
  }

  // Assumes that delegate doesn't have null elements and comparator.
  static <E> ImmutableSortedSet<E> unsafeDelegateSortedSet(
      SortedSet<E> delegate, boolean isSubset) {
    return delegate.isEmpty()
        ? emptySet(delegate.comparator())
        : new RegularImmutableSortedSet<E>(delegate, isSubset);
  }

  private final transient SortedSet<E> sortedDelegate;

    private final Future<?> delegate;

    FutureAsCancellable(Future<?> delegate) {
      this.delegate = delegate;
    }

    @Override
    @SuppressWarnings("Interruption") // We are propagating an interrupt from a caller.
    public void cancel(boolean mayInterruptIfRunning) {
      delegate.cancel(mayInterruptIfRunning);
    }

    @Override

  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