Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(Ordering.natural(), keyFunction, valueFunction);
  }

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

      Collector<T, ?, ImmutableSortedMap<K, V>> toImmutableSortedMap(
          Function<? super T, ? extends K> keyFunction,
          Function<? super T, ? extends V> valueFunction) {
    return CollectCollectors.toImmutableSortedMap(Ordering.natural(), keyFunction, valueFunction);
  }

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

          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

          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