Method offer

examples/notify-sample.cpp:86–91

    }

    void offer() {
        std::scoped_lock its_lock(notify_mutex_);
        app_->offer_service(SAMPLE_SERVICE_ID, SAMPLE_INSTANCE_ID);
        is_offered_ = true;
        notify_condition_.notify_one();
    }

    void stop_offer() {
        app_->stop_offer_service(SAMPLE_SERVICE_ID, SAMPLE_INSTANCE_ID);