FluentIterable.index equivalent

[perceptron8]

http://google.github.io/guava/releases/24.1-jre/api/docs/com/google/common/collect/FluentIterable.html#index-com.google.common.base.Function-

Stream equivalent: stream.collect(Collectors.groupingBy(keyFunction)) behaves similarly, but returns a mutable Map<K, List<E>> instead, and may not preserve the order of entries).

Since 21.0, stream.collect(ImmutableListMultimap.toImmutableListMultimap(keyFunction, v -> v)) may be used.

[lowasser]

It's not clear to me what this is asking for -- just a shortcut that doesn't require the v -> v?

[perceptron8]

It seems to me that it was rather about updating javadoc. The note about stream equivalent appeared in 19.0. Since 21.0, instead of stream.collect(Collectors.groupingBy(keyFunction)) you can use stream.collect(ImmutableListMultimap.toImmutableListMultimap(keyFunction, v -> v)), which is even "more equivalent", as it preserves the order of entries and gives you ImmutableListMultimap<K, E>, not mutable Map<K, List<E>>.

Shortcut that doesn't require v -> v would be handy, but I don't insist.