    dw2->resize(QSize(400, 400));

    auto dw3 = new KDDockWidgets::DockWidgetQuick("Dock #3");
    dw3->setWidget(QStringLiteral("qrc:/Guest3.qml"));

    auto mainWindow = static_cast<KDDockWidgets::MainWindowMDI*>(KDDockWidgets::DockRegistry::self()->mainwindows().constFirst());