Comparator<? super K> comparator,
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(comparator, keyFunction, valueFunction);
  }

  /**
   * Returns a {@link Collector} that accumulates elements into an {@code ImmutableSortedMap} whose

   * @throws NullPointerException if any element of {@code keys} is {@code null}, or if {@code
   *     valueFunction} produces {@code null} for any key
   * @since 14.0
   */
  public static <K, V> ImmutableMap<K, V> toMap(
      Iterable<K> keys, Function<? super K, V> valueFunction) {
    return toMap(keys.iterator(), valueFunction);
  }

  /**

   * @throws NullPointerException if any element of {@code keys} is {@code null}, or if {@code
   *     valueFunction} produces {@code null} for any key
   * @since 14.0
   */
  public static <K, V> ImmutableMap<K, V> toMap(
      Iterable<K> keys, Function<? super K, V> valueFunction) {
    return toMap(keys.iterator(), valueFunction);
  }

  /**

          java.util.function.Function<? super T, ? extends K> keyFunction,
          java.util.function.Function<? super T, ? extends V> valueFunction,
          java.util.function.Supplier<M> multimapSupplier) {
    return CollectCollectors.<T, K, V, M>toMultimap(keyFunction, valueFunction, multimapSupplier);
  }

  /**
   * Returns a {@code Collector} accumulating entries into a {@code Multimap} generated from the