docs: private synchronized void merge(Identity identity, Map<Class, BatchObject> data, Object item) {
          Class clazz = item.getClass();
          BatchObject batchObject = data.get(clazz);
          // 初始化一下对象
          if (batchObject == null) {
              batchObject = initBatchObject(identity, clazz);
              data.put(clazz, batchObject);
          }
  
          // 进行merge处理
          if (batchObject instanceof RowBatch) {
              ((RowBatch) batchObject).merge((EventData) item);
          } else if (batchObject instanceof FileBatch) {
              ((FileBatch) batchObject).getFiles().add((FileData) item);
          } else {
              throw new TransformException("no support Data[" + clazz.getName() + "]");
          }
      }