Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    checkNotNull(keyFunction, "keyFunction");
    checkNotNull(valueFunction, "valueFunction");
    return Collector.of(
        ImmutableListMultimap::<K, V>builder,
        (builder, t) -> builder.put(keyFunction.apply(t), valueFunction.apply(t)),
        ImmutableListMultimap.Builder::combine,

      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  // Casting to any type is safe because the set will never hold any elements.
  @SuppressWarnings("unchecked")
  public static <K, V> ImmutableBiMap<K, V> of() {

          Function<? super T, ? extends V> valueFunction,
          BinaryOperator<V> mergeFunction) {
    checkNotNull(comparator);
    checkNotNull(keyFunction);
    checkNotNull(valueFunction);
    checkNotNull(mergeFunction);
    return Collectors.collectingAndThen(
        Collectors.toMap(
            keyFunction, valueFunction, mergeFunction, () -> new TreeMap<K, V>(comparator)),

          Function<? super T, ? extends R> rowFunction,
          Function<? super T, ? extends C> columnFunction,
          Function<? super T, ? extends V> valueFunction) {
    return TableCollectors.toImmutableTable(rowFunction, columnFunction, valueFunction);
  }

  /**
   * Returns a {@code Collector} that accumulates elements into an {@code ImmutableTable}. Each

   * k, valueFunction))}. {@code ImmutableMap.copyOf(stream.collect(Collectors.toMap(k -> k,
   * valueFunction)))} behaves similarly, but may not preserve the order of entries.
   *
   * @throws NullPointerException if any element of this iterable is {@code null}, or if {@code
   *     valueFunction} produces {@code null} for any key
   * @since 14.0
   */

          java.util.function.Function<? super T, ? extends C> columnFunction,
          java.util.function.Function<? super T, ? extends V> valueFunction,
          java.util.function.Supplier<I> tableSupplier) {
    return TableCollectors.<T, R, C, V, I>toTable(
        rowFunction, columnFunction, valueFunction, tableSupplier);
  }

  /**
   * Returns a {@link Collector} that accumulates elements into a {@code Table} created using the

      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  /**
   * Returns the empty bimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

          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

      Collector<T, ?, ImmutableBiMap<K, V>> toImmutableBiMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableBiMap(keyFunction, valueFunction);
  }

  /**
   * Returns the empty bimap.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */

   * @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);
  }

  /**