@Override
    public void deleteAll() {
        FunctionUtils.doAndHandle(__ -> {
            val col = firestore.collection(collectionName);
            firestore.recursiveDelete(col).get();
        });
    }
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