code: public GetQYUserInviteResponse invite(String userid){
          BeanUtil.requireNonNull(userid, "userid is null");
          GetQYUserInviteResponse response;
          String url = BASE_API_URL + "cgi-bin/invite/send?access_token=#";
          final Map<String, String> params = new HashMap<String, String>();
          params.put("userid", userid);
          BaseResponse r = executePost(url, JSONUtil.toJson(params));
          String resultJson = isSuccess(r.getErrcode()) ? r.getErrmsg() : r.toJsonString();
          response = JSONUtil.toBean(resultJson, GetQYUserInviteResponse.class);
          return response;
      }
docs: 邀请成员关注。返回值type为1时表示微信邀请，2为邮件邀请
  @param userid 用户ID
  @return 邀请结果