docs: private void unregisterCachedServiceInstance(
              String serviceName, String providerId) {
          try {
              write.lock();
              ServiceInstanceId id = new ServiceInstanceId(serviceName, providerId);
              getCacheServiceInstances().remove(id);
              LOGGER.debug(
                      "delete cached ProvidedServiceInstance, serviceName={}, providerId={}.",
                      serviceName, providerId);
          } finally {
              write.unlock();
          }
      }