docs: public String createRuleMenu(RuleMenu menu) {
          String url = WxEndpoint.get("url.menu.create.condition");
          if(menu.getRule() == null) {
              throw new IllegalArgumentException("个性化菜单rule不能为空");
          }
          String json = JsonMapper.nonEmptyMapper().toJson(menu);
          logger.debug("create rule menu: {}", json);
          String response = wxClient.post(url, json);
          Map<String, Object> map = JsonMapper.defaultMapper().json2Map(response);
          if(map.containsKey("menuid")) {
              return (String) map.get("menuid");
          } else {
              throw new WxRuntimeException(999, "create rule menu failed");
          }
      }