code: public void selfRegister() {
          LocalUnitsManager.unitMap(unitMap -> {
              unitMap.forEach((groupName, unitsIgnored) -> {
                  try {
                      ServiceInstance<GroupProxy> serviceInstance = ZkServiceInstanceAdaptor.thisCuratorServiceInstance(groupName);
                      serviceDiscovery.registerService(serviceInstance);
                  } catch (Exception e) {
                      LOG.error(e);
                      //the registration should not be interrupted due to one error.
                  }
              });
          });
      }
docs: 向zk server注册本节点内所有units；
  注意，必须先init然后才可以执行本方法