return asList(contents).contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> collection) {
    if (!allowNulls) {
      for (Object object : collection) {
        // behave badly
        if (object == null) {
          throw new NullPointerException();
        }
      }
    }
    return super.containsAll(collection);
  }

  @Override
  public Iterator<E> iterator() {

    public boolean add(E element) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.add(element);
    }

    @Override
    public boolean containsAll(Collection<?> collection) {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.containsAll(collection);
    }

    @Override
    public boolean addAll(Collection<? extends E> collection) {
      assertTrue(Thread.holdsLock(mutex));

  }

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

  @Override
  public boolean containsAll(Collection<?> targets) {
    return delegate.containsAll(targets);
  }

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

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

    return delegate.contains(object);
  }

  @Override
  public boolean containsAll(Collection<?> collection) {
    if (collection instanceof ImmutableEnumSet<?>) {
      collection = ((ImmutableEnumSet<?>) collection).delegate;
    }
    return delegate.containsAll(collection);
  }

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

        parent.clear();
    }

    @Override
    public boolean contains(final Object o) {
        return parent.contains(o);
    }

    @Override
    public boolean containsAll(final Collection<?> c) {
        return parent.containsAll(c);
    }

    @Override
    public boolean equals(final Object o) {
        return parent.equals(o);
    }

    @Override

  @Override
  public boolean contains(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.contains(o);
  }

  @Override
  public boolean containsAll(Collection<?> c) {
    assertTrue(Thread.holdsLock(mutex));
    return super.containsAll(c);
  }

  @Override
  public boolean isEmpty() {
    assertTrue(Thread.holdsLock(mutex));
    return super.isEmpty();
  }

  /*

  @Override
  public boolean contains(@Nullable Object o) {
    assertTrue(Thread.holdsLock(mutex));
    return super.contains(o);
  }

  @Override
  public boolean containsAll(Collection<?> c) {
    assertTrue(Thread.holdsLock(mutex));
    return super.containsAll(c);
  }

  @Override
  public boolean isEmpty() {
    assertTrue(Thread.holdsLock(mutex));
    return super.isEmpty();
  }

  /*

      assertTrue(entrySet.containsAll(new HashSet<Entry<K, V>>(entrySet)));
      assertTrue(entrySet.equals(new HashSet<Entry<K, V>>(entrySet)));
    }

    Object[] entrySetToArray1 = entrySet.toArray();
    assertEquals(map.size(), entrySetToArray1.length);
    assertTrue(asList(entrySetToArray1).containsAll(entrySet));

    assertEquals(oldValues, new ArrayList<V>(multimap().replaceValues(k0(), values)));
    assertEquals(size - oldValues.size() + multimap().get(k0()).size(), multimap().size());
    assertTrue(multimap().get(k0()).containsAll(values));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE})
  public void testReplaceNonEmptyValues() {
    List<K> keys = copyToList(multimap().keySet());

    for (Set<Integer> subset : Sets.powerSet(ImmutableSet.of(1, 2, 3))) {
      assertTrue(set.containsAll(subset));
    }
    for (Set<Integer> subset : Sets.powerSet(ImmutableSet.of(1, 2, 3))) {
      assertFalse(set.containsAll(Sets.union(subset, ImmutableSet.of(9))));
    }
  }

  // TODO: https://youtrack.jetbrains.com/issue/KT-71001/ - Enable when Kotlin throws expected CCE.