docs: private void sendRegisterRequest() {
      StreamManager.RegisterInstanceRequest request =
          StreamManager.RegisterInstanceRequest.newBuilder().
              setInstance(instance).setTopologyName(topologyName).setTopologyId(topologyId).
              build();
  
      // The timeout would be the reconnect-interval-seconds
      sendRequest(request, null,
          StreamManager.RegisterInstanceResponse.newBuilder(),
          systemConfig.getInstanceReconnectStreammgrInterval());
    }