@Override
    public int hashCode() {
        return Objects.hash(super.hashCode(),
                scyllaDbRef,
                description,
                stateType,
                condense,
                condenseAge,
                condenseTimeUnit,
                retainForever,
                retainAge,
                retainTimeUnit);
    }
@return A new builder for creating a {@link DocRef} for this document's type.
stroom-core-shared/src/main/java/stroom/state/shared/StateDoc.java