// We block and wait for samples to arrive, when the time is up we send the request again
        //! [wait and check if the client triggered]
        auto notificationVector = waitset.timedWait(iox::units::Duration::fromSeconds(5));
        if (notificationVector.empty()) {
            std::cout << "time out occur" << std::endl;
            // TODO: timeout occur, so how can i drop current request
            continue;
        }