api/kr.toxicity.model.api.util/CollectionUtil/group

group

@NotNull

@Unmodifiable

open fun <K, E> group(@NotNull stream: @NotNull Stream<E>, @NotNull keyMapper: @NotNull (E) -> K): @NotNull @Unmodifiable Map<K, List<E>>

Groups stream by some key

Return

unmodifiable grouped map

Parameters

stream

stream

keyMapper

key mapper

<K>

key

<E>

element