class SubscriptionDelegate {

    Subscriber getSubscriber(Identity subscriberIdentity) {
        // cg/bb : IS THREAD_SAFE because Subscriber per Identity
        Subscriber subscriber = subscriberDao.findSubscriber(subscriberIdentity);
        if (subscriber == null) {
            subscriber = subscriberDao.createAndSaveSubscriber(subscriberIdentity);
        }
        return subscriber;
    }

}