}

  @Override
  public void testEntrySetRemoveAllNullFromEmpty() {
    try {
      super.testEntrySetRemoveAllNullFromEmpty();
    } catch (RuntimeException tolerated) {
      // GWT's TreeMap.entrySet().removeAll(null) doesn't throws NPE.
    }
  }

  @Override
  public void testEntrySetRetainAllNullFromEmpty() {
    try {
      super.testEntrySetRetainAllNullFromEmpty();
    } catch (RuntimeException tolerated) {

  }

  /**
   * A sensible definition of {@link #removeAll} in terms of {@link #iterator}, using the iterator's
   * {@code remove} method. If you override {@link #iterator}, you may wish to override {@link
   * #removeAll} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardRemoveAll(Collection<?> collection) {
    return Iterators.removeAll(iterator(), collection);
  }

  /**

  }

  /**
   * A sensible definition of {@link #removeAll} in terms of {@link #iterator}, using the iterator's
   * {@code remove} method. If you override {@link #iterator}, you may wish to override {@link
   * #removeAll} to forward to this implementation.
   *
   * @since 7.0
   */
  protected boolean standardRemoveAll(Collection<?> collection) {
    return Iterators.removeAll(iterator(), collection);
  }

  /**

    }
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    return asMap().get(key) != null;
  }

  @Override
  public Collection<V> removeAll(@Nullable Object key) {
    return MoreObjects.firstNonNull(asMap().remove(key), unmodifiableEmptyCollection());
  }

  @SuppressWarnings("EmptyList") // ImmutableList doesn't support nullable element types

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

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

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

  }

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

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

  @CanIgnoreReturnValue
  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return delegate().replaceValues(key, values);

        public Iterator<K> iterator() {
          return Iterators.unmodifiableIterator(delegate.keySet().iterator());
        }

        @Override
        public boolean removeAll(Collection<?> c) {
          return delegate.keySet().removeAll(c);
        }

        @Override
        public boolean retainAll(Collection<?> c) {
          return delegate.keySet().retainAll(c);
        }
      };
    }

  }

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

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

  @CanIgnoreReturnValue
  @Override
  public Set<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return delegate().replaceValues(key, values);

  }

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

  /**
   * A sensible definition of {@link #removeAll} in terms of {@link #iterator} and {@link #remove}.
   * If you override {@code iterator} or {@code remove}, you may wish to override {@link #removeAll}
   * to forward to this implementation.
   *
   * @since 7.0 (this version overrides the {@code ForwardingCollection} version as of 12.0)
   */

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

  @Override
  public SortedSet<V> removeAll(@Nullable Object key) {
    return delegate().removeAll(key);
  }

  @Override
  public SortedSet<V> replaceValues(@ParametricNullness K key, Iterable<? extends V> values) {
    return delegate().replaceValues(key, values);
  }