in serverless-workflow-examples/serverless-workflow-newsletter-subscription/subscription-service/src/main/java/org/acme/newsletter/subscription/service/InMemorySubscriptionRepository.java [55:61]
public Optional<Subscription> fetchByIdAndEmail(String id, String email) {
final Optional<Subscription> subscription = Optional.ofNullable(subscriptionMap.getOrDefault(email, null));
if (subscription.isPresent() && !id.equals(subscription.get().getId())) {
return Optional.empty();
}
return subscription;
}