guava/src/com/google/common/collect/Streams.java
@Beta
  @Deprecated
  public static <T> Stream<T> stream(Collection<T> collection) {
    return collection.stream();
  }
@Beta
  @Deprecated
  public static <T> Stream<T> stream(Collection<T> collection) {
    return collection.stream();
  }
Returns {@link Collection#stream}.

@deprecated There is no reason to use this; just invoke {@code collection.stream()} directly.