@Override
        public String toSerialForm() {
            return "uca(" + getName() + ',' + locale + ',' +
                   ((strength != Strength.UNDEFINED) ? strength.toString() : "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