MenuBar has no properties for it's dimension and position

There is no width, height, x, y and anchors properties. There is __contentItem, but it is internal, so it is not intended for use.
There is an qml component ApplicationWindow with the following description: "ApplicationWindow is a Window that adds convenience for positioning items, such as MenuBar, ToolBar, and StatusBar in a platform independent manner." But this is wrong, because this not item for CONVENIENCE, this is the ONLY WAY to use MenuBar properly.
If I use Window instead and I want to add MenuBar, I must use that internal properties.
Also, if I have some customized window, that uses derived from QQuickWindow class, I can't use ApplicationWindow.