How to Terminate QtWebEngine Before Exiting

#include <QtCore>
#include <QtWidgets\QMainWindow>
#include <QtWebEngine\QtWebEngine>
#include <QtWebEngineWidgets>

#define _CRTDBG_MAP_ALLOC

int main( int argc, char * argv[] )
{
	_CrtSetDbgFlag( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ); // enable memory leak checking

	int result = 0;
	{
		QApplication app( argc, argv );
		QtWebEngine::initialize(); // reports leaks - likely not closed correctly on exit
		QMainWindow mainWindow;

		QWebEngineView *webView = new QWebEngineView; // more leaks...
		webView->load( QUrl( "https://www.qt.io" ) ); // even more leaks...

		mainWindow.setCentralWidget( webView );
		mainWindow.resize( 800, 600 );
		mainWindow.show();


		result = app.exec();
	}
	// expected Qt to have finished offloading here
	
	return result;
}