public Optional<Rule> partialResolve(FetchVector fetchVector) {
        List<Condition> newConditions = new ArrayList<>();
        for (var condition : andConditions) {
            if (fetchVector.hasDimension(condition.dimension())) {
                if (!condition.test(fetchVector)) {
                    return Optional.empty();
                }
            } else {
                newConditions.add(condition);
            }
        }

        return Optional.of(new Rule(valueToApply, newConditions));
    }
Returns a copy of this rule without those conditions that can be resolved by the fetch vector.  Returns empty
if any of those conditions are false.
flags/src/main/java/com/yahoo/vespa/flags/json/Rule.java