public static <T extends Comparable<? super T>> T min(T first, T second) {
        return first.compareTo(second) <= 0 ? first : second;
    }
Returns the least element, or {@code first} if they are equal according to
{@link Comparable#compareTo(Object) compareTo}.
vespajlib/src/main/java/com/yahoo/collections/Comparables.java