public Map<String, Object> values() {
        if (values == null) {
            if (frozen)
                return Map.of();
            else
                values = new HashMap<>();
        }
        return values;
    }
Returns the live reference to the values of this. This may be modified
if this is not frozen.
container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileVariant.java