@JsonIgnore
    public List<DataRetentionRule> getActiveRules() {
        return NullSafe.stream(rules)
                .filter(DataRetentionRule::isEnabled)
                .collect(Collectors.toList());
    }
@return A new builder for creating a {@link DocRef} for this document's type.
stroom-core-shared/src/main/java/stroom/data/retention/shared/DataRetentionRules.java