public static IntStream concat(IntStream a, IntStream b) { Objects.requireNonNull(a); Objects.requireNonNull(b); Spliterator.OfInt split = new Streams.ConcatSpliterator.OfInt( a.spliterator(), b.spliterator()); IntStream stream = StreamSupport.intStream(split, a.isParallel() || b.isParallel()); return stream.onClose(Streams.composedClose(a, b)); }