@Override
        public boolean equals(Object o) {
            if (!(o instanceof FieldOrder other)) return false;
            return other.sortOrder.equals(sortOrder) && other.fieldSorter.equals(fieldSorter) &&
                    other.missingValueSettings.equals(missingValueSettings);
        }
Decide if sortorder is ascending or not.
container-search/src/main/java/com/yahoo/search/query/Sorting.java