title: How to use Overlay.modal in Qt5.10
body: <p>The old overlay property is Obsoleted.</p>
  
  <p>But how to use the new one in Qt5.10?</p>
  
  <p><a href="https://doc.qt.io/qt-5/qml-qtquick-controls2-overlay.html" rel="nofollow noreferrer">https://doc.qt.io/qt-5/qml-qtquick-controls2-overlay.html</a></p>