@Nonnull
    public static <T> AggregateOperation1<T, MutableReference<T>, T> minBy(
            @Nonnull ComparatorEx<? super T> comparator
    ) {
        checkSerializable(comparator, "comparator");
        return maxBy(comparator.reversed());
    }
@Test
    public void when_minBy() {
        validateOpWithoutDeduct(minBy(naturalOrder()), MutableReference::get,
                10L, 11L, 10L, 10L, 10L);
    }