public CompletableFuture<Boolean> addUserToOrganization(String user_id, String organization_id) {
        CompletableFuture<Boolean> r1 =
                db.updateArrayField(ORGANIZATIONS_COLLECTION_KEY + organization_id, ADMIN_KEY, user_id);
        CompletableFuture<Boolean> r2 =
                db.updateArrayField(USERS_COLLECTION_KEY + user_id, USER_ORGANIZATIONS, organization_id);