docs: public boolean single(StageType stage, EtlEventData eventData) {
          Assert.notNull(eventData);
          eventData.setCurrNid(ArbitrateConfigUtils.getCurrentNid());
  
          StageSingleEvent event = new StageSingleEvent(ArbitrateEventType.stageSingle);
          event.setPipelineId(eventData.getPipelineId());
          event.setStage(stage);
          event.setData(eventData);
  
          if (isLocal(eventData.getNextNid())) {// 判断是否为本地jvm
              return onStageSingle(event);
          } else {
              return (Boolean) arbitrateCommmunicationClient.call(eventData.getNextNid(), event);// rpc通知下一个节点
          }
      }