static private int strength2Collator(Strength strength) {
            return switch (strength) {
                case PRIMARY -> Collator.PRIMARY;
                case SECONDARY -> Collator.SECONDARY;
                case TERTIARY -> Collator.TERTIARY;
                case QUATERNARY -> Collator.QUATERNARY;
                case IDENTICAL -> Collator.IDENTICAL;
                case UNDEFINED -> Collator.PRIMARY;
            };
        }
Returns the serial form of this which contains all information needed to reconstruct this sorter
container-search/src/main/java/com/yahoo/search/query/Sorting.java