assertTrue(Thread.holdsLock(mutex));
      return super.toString();
    }

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

    @Override
    public int hashCode() {
      assertTrue(Thread.holdsLock(mutex));
      return super.hashCode();
    }

    @Override
    public int size() {

  private final transient Comparator<? super K> comparator;

  ImmutableSortedMap(SortedMap<K, V> delegate, Comparator<? super K> comparator) {
    super(delegate);
    this.comparator = comparator;
    this.sortedDelegate = delegate;
  }

  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Comparator<? super K> comparator,

      extends AbstractCatchingFuture<V, X, Function<? super X, ? extends V>, V> {
    CatchingFuture(
        ListenableFuture<? extends V> input,
        Class<X> exceptionType,
        Function<? super X, ? extends V> fallback) {
      super(input, exceptionType, fallback);
    }

    @Override
    @ParametricNullness
    V doFallback(Function<? super X, ? extends V> fallback, X cause) throws Exception {

  @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) {

  @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) {

  FilteredEntrySetMultimap(SetMultimap<K, V> unfiltered, Predicate<? super Entry<K, V>> predicate) {
    super(unfiltered, predicate);
  }

  @Override
  public SetMultimap<K, V> unfiltered() {
    return (SetMultimap<K, V>) unfiltered;
  }

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

  @Override
  public Set<V> removeAll(@CheckForNull Object key) {

  FilteredKeySetMultimap(SetMultimap<K, V> unfiltered, Predicate<? super K> keyPredicate) {
    super(unfiltered, keyPredicate);
  }

  @Override
  public SetMultimap<K, V> unfiltered() {
    return (SetMultimap<K, V>) unfiltered;
  }

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

  @Override
  public Set<V> removeAll(@CheckForNull Object key) {

    return (Set<V>) super.get(key);
  }

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
   */
  @Override
  public Set<Entry<K, V>> entries() {
    return (Set<Entry<K, V>>) super.entries();
  }

  /**
   * {@inheritDoc}

  static <T extends @Nullable Object, E>
      Collector<T, ?, ImmutableSortedMultiset<E>> toImmutableSortedMultiset(
          Comparator<? super E> comparator,
          Function<? super T, ? extends E> elementFunction,
          ToIntFunction<? super T> countFunction) {
    checkNotNull(comparator);
    checkNotNull(elementFunction);
    checkNotNull(countFunction);
    return Collector.of(

    super(checkNotNull(out));
    this.options = ImmutableSet.copyOf(options);
    throwIf(OPEN_THROWS);
  }

  public boolean closed() {
    return closed;
  }

  @Override
  public void write(byte[] b, int off, int len) throws IOException {
    throwIf(closed);
    throwIf(WRITE_THROWS);
    super.write(b, off, len);
  }

  @Override