docs: public UserPagination list(String nextOpenId){
          String url = WxEndpoint.get("url.blacklist.list");
          Map<String, Object> body = new HashMap<>();
          body.put("begin_openid", nextOpenId);
          logger.debug("list all black list: {}", nextOpenId);
          String response = wxClient.post(url, JsonMapper.defaultMapper().toJson(body));
          return JsonMapper.defaultMapper().fromJson(response, UserPagination.class);
      }