@Override
    public RegisteredService findServiceById(final long id) {
        return FunctionUtils.doUnchecked(() -> {
            val documentSnapshot = firestore.collection(collectionName)
                .document(String.valueOf(id)).get().get();
            val document = documentSnapshot.getString("json");
            return StringUtils.isNotBlank(document) ? serializer.from(document) : null;
        });
    }
This is {@link GoogleCloudFirestoreServiceRegistry}.

@author Misagh Moayyed
@since 7.0.0
support/cas-server-support-gcp-firestore-service-registry/src/main/java/org/apereo/cas/services/GoogleCloudFirestoreServiceRegistry.java