code: private ConsulResponse<List<ConsulService>> lookupConsulService(String serviceName, Long lastConsulIndexId) {
          ConsulResponse<List<ConsulService>> response = client.lookupHealthService(serviceName, null, lastConsulIndexId, getConsulToken());
          return response;
      }
docs: directly fetch consul service data.
  
  @param serviceName
  @return ConsulResponse or null