Qt application blocks macos shutdown, restart

Description: Qt application interrupts macOS from restarting or shut downing if any clean-up code in aboutToQuit signal emitted time take some time(from my side 200 ms is enough). OS always shows  

Example:

QObject::connect(qApp, &QGuiApplication::aboutToQuit, qApp, [](){
        // long time close opperation
        // write to file
        // save data in db
        // generation data and save on disk
        // and so on
        std::this_thread::sleep_for(std::chrono::milliseconds(10000));
    });

Steps to reproduce:
1 Run attached application
2 Restart macOS

Expected result: It is possible to clean-up code in any way without any interruptions and additional warnings from OS side.

NOTE: - (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
return NSTerminateNow or NSTerminateCancel

Suggestion: Consider returning NSTerminateLater and call 
[NSApp replyToApplicationShouldTerminate:YES];
in ~QApplication for example