Extend Page container

[poucz]

Hello,
I'm using Page container for design my application.
Now I would like to extend Page by adding menu-section.

I would like to behavior MyPage.qml was same like Page.
Usage:

MyPage{
header:Text{
        text:"Hello"
    }

menu:Text{
        text:"This is menu- here will be Column of button for example"
    }

}

How Can I do It right way?

Now I do it like this: (but I suppose not good way)

//MyPage.qml
Page {
    property alias menuRect: menuRect
    property alias contentRect: contentRect
    Rectangle{
        id: menuRect
        anchors.top: parent.top
        anchors.bottom: parent.bottom
        anchors.right: parent.right
        width: 100
    }
    Rectangle{
        id: contentRect
        anchors.top: parent.top
        anchors.bottom: parent.bottom
        anchors.left: parent.left
        anchors.right: menuRect.left
    }
}

//use it: FirstPage.qml
MyPage {
  Text{
        anchors.fill:menuRect
        text:"Hello"
    }

  Text{
        anchors.fill:contentRect
        text:"Hello"
     }
}