static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Comparator<? super K> comparator,
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(comparator, keyFunction, valueFunction);
  }

  /**

      implements SortedSet<E> {
    SynchronizedSortedSet(SortedSet<E> delegate, @CheckForNull Object mutex) {
      super(delegate, mutex);
    }

    @Override
    SortedSet<E> delegate() {
      return (SortedSet<E>) super.delegate();
    }

    @Override
    @CheckForNull
    public Comparator<? super E> comparator() {
      synchronized (mutex) {
        return delegate().comparator();
      }
    }

    }
    return resolver;
  }

  private TypeToken<? super T> getSupertypeFromUpperBounds(
      Class<? super T> supertype, Type[] upperBounds) {
    for (Type upperBound : upperBounds) {
      @SuppressWarnings("unchecked") // T's upperbound is <? super T>.
      TypeToken<? super T> bound = (TypeToken<? super T>) of(upperBound);
      if (bound.isSubtypeOf(supertype)) {

   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Comparator<? super K> comparator,
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(comparator, keyFunction, valueFunction);
  }

  /**

    assertAssignable(
        new TypeToken<ArrayList<? super Number>>() {}, new TypeToken<List<? super N11>>() {});

    // ? super Number
    assertNotAssignable(
        new TypeToken<ArrayList<N11>>() {}, new TypeToken<List<? super Number>>() {});
    assertAssignable(
        new TypeToken<ArrayList<Number>>() {}, new TypeToken<List<? super Number>>() {});
    assertAssignable(

      extends AbstractMultimap<K, V2> {
    final Multimap<K, V1> fromMultimap;
    final EntryTransformer<? super K, ? super V1, V2> transformer;

    TransformedEntriesMultimap(
        Multimap<K, V1> fromMultimap,
        final EntryTransformer<? super K, ? super V1, V2> transformer) {
      this.fromMultimap = checkNotNull(fromMultimap);
      this.transformer = checkNotNull(transformer);
    }

    assertAssignable(
        new TypeToken<ArrayList<? super Number>>() {}, new TypeToken<List<? super N11>>() {});

    // ? super Number
    assertNotAssignable(
        new TypeToken<ArrayList<N11>>() {}, new TypeToken<List<? super Number>>() {});
    assertAssignable(
        new TypeToken<ArrayList<Number>>() {}, new TypeToken<List<? super Number>>() {});
    assertAssignable(

    private Invisible() {
      super("CharMatcher.invisible()", RANGE_STARTS.toCharArray(), RANGE_ENDS.toCharArray());
    }
  }

  /** Implementation of {@link #singleWidth()}. */
  private static final class SingleWidth extends RangesMatcher {

    static final CharMatcher INSTANCE = new SingleWidth();

    private SingleWidth() {
      super(
          "CharMatcher.singleWidth()",

      implements StrongValueEntry<K, V, StrongKeyStrongValueEntry<K, V>> {
    @CheckForNull private volatile V value = null;

    private StrongKeyStrongValueEntry(K key, int hash) {
      super(key, hash);
    }

    @Override
    @CheckForNull
    public final V getValue() {
      return value;
    }

    private static final class LinkedStrongKeyStrongValueEntry<K, V>

    private Invisible() {
      super("CharMatcher.invisible()", RANGE_STARTS.toCharArray(), RANGE_ENDS.toCharArray());
    }
  }

  /** Implementation of {@link #singleWidth()}. */
  private static final class SingleWidth extends RangesMatcher {

    static final CharMatcher INSTANCE = new SingleWidth();

    private SingleWidth() {
      super(
          "CharMatcher.singleWidth()",