docs: @Override
      public ServiceInstance queryInstanceByName(String serviceName, ServiceInstanceQuery query)
              throws ServiceException {
          if(! isStarted){
              ServiceDirectoryError error = new ServiceDirectoryError(ErrorCode.SERVICE_DIRECTORY_MANAGER_FACTORY_CLOSED);
              throw new ServiceException(error);
          }
  
          ServiceQueryRRLoadBalancer lb = lbManager.getServiceQueryRRLoadBalancer(serviceName, query);
          return lb.vote();
  
      }