public static <T extends Comparable<? super T>> T requireAtMost(T value, String description, T upper) {
        return require(upper.compareTo(value) >= 0, value, description + " must be at most '" + upper + "'");
    }
Requires the value to be at most the upper bound.
vespajlib/src/main/java/ai/vespa/validation/Validation.java