public List<EpTaskStepHistory> listEpTaskStepHistory(String historyTaskId) {
   if (StringUtils.isBlank(historyTaskId)) {
     throw new BusinessException("id", ErrorCode.PARAMETER_NOT_FOUND);
   }
   EpTaskStepHistoryExample example = new EpTaskStepHistoryExample();
   EpTaskStepHistoryExample.Criteria criteria = example.createCriteria();
   criteria.andHistoryTaskIdEqualTo(historyTaskId);
   List<EpTaskStepHistory> list = epTaskStepHistoryDAO.selectByExample(example);
   return list;
 }