docs: public static <T> Collector<T, ?, IntMoments>
  	toIntMoments(final ToIntFunction<? super T> mapper) {
  		requireNonNull(mapper);
  		return Collector.of(
  			IntMomentStatistics::new,
  			(a, b) -> a.accept(mapper.applyAsInt(b)),
  			IntMomentStatistics::combine,
  			IntMoments::of
  		);
  	}