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

  public static <T extends @Nullable Object, K, V>
      Collector<T, ?, ImmutableMap<K, V>> toImmutableMap(
          Function<? super T, ? extends K> keyFunction,

  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public static <E extends Comparable<? super E>>
      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }

  /**
   * Returns an empty immutable range set.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")

   * ranges will be merged.
   *
   * @since 23.1
   */
  public static <E extends Comparable<? super E>>
      Collector<Range<E>, ?, ImmutableRangeSet<E>> toImmutableRangeSet() {
    return CollectCollectors.toImmutableRangeSet();
  }

  /**
   * Returns an empty immutable range set.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  @SuppressWarnings("unchecked")

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

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

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

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