@Override
    public String toString() {
        return "StateDoc{" +
               "description='" + description + '\'' +
               ", stateType=" + stateType +
               ", settings=" + settings +
               '}';
    }
@return A new builder for creating a {@link DocRef} for this document's type.
stroom-core-shared/src/main/java/stroom/planb/shared/PlanBDoc.java