docs: public List<User> batchGet(List<Map<String, String>> openIds) {
          if(openIds.size() > 100) {
              throw new WxRuntimeException(999, "批量获取用户基本信息。最多支持一次拉取100条");
          }
  
          String url = WxEndpoint.get("url.user.batchget");
          String body = "{\"user_list\":%s}";
          String json = JsonMapper.defaultMapper().toJson(openIds);
  
          logger.debug("batch get users.");
          String response = wxClient.post(url, String.format(body, json));
          UsersWrapper usersWrapper = JsonMapper.defaultMapper().fromJson(response, UsersWrapper.class);
          return usersWrapper.getList();
      }