Item.grabToImage() does not work on ApplicationWindow items

import QtQuick 2.7
import QtQuick.Controls 2.2
import QtQuick.Layouts 1.3
import QtQuick.Window 2.0
import QtMultimedia 5.8
import Qt.labs.settings 1.0
import QtGraphicalEffects 1.0


ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")
    id:root


    property alias theContentItemContent: theContentItemContent
    Rectangle
    {
        id: theContentItemContent
        color: "red"
        width: 100
        height: width
        anchors.centerIn: parent
        MouseArea
        {
            anchors.fill: parent
//            onClicked: root./*theContentItemContent*/overlay.grabToImage(function(img) {console.log("grab callback called"); rawIHMImage.source = img.url; work(); }, Qt.size(500, 500) )
            // <Unknown File>: QML QQuickOverlay: grabToImage: item has no QML engine
//            onClicked: root./*theContentItemContent*/contentItem.grabToImage(function(img) {console.log("grab callback called"); rawIHMImage.source = img.url; work(); }, Qt.size(500, 500) )
            //<Unknown File>: QML QQuickItem: grabToImage: item has no QML engine
            onClicked: root.theContentItemContent.grabToImage(function(img) {console.log("grab callback called"); rawIHMImage.source = img.url; work(); }, Qt.size(500, 500) )
        }
    }


    Image
    {
        parent: overlay
        id: rawIHMImage
        anchors.horizontalCenter:   theContentItemContent.horizontalCenter
        anchors.top: theContentItemContent.bottom
        visible: true
        onSourceChanged: console.log(source)
        width: 150
        height: width
        y:200
        z:1500
        Text {
            id: name
            text: qsTr("text")
        }
    }


    function work() { console.log("work called"); rawIHMImage.width *= .95; rawIHMImage2.visible = false; shaderCopy.grabToImage(function(img) {console.log("grab callback 2 called"); rawIHMImage2.source = img.url; rawIHMImage2.visible = true; } )}


    Image
    {
        parent: overlay
        id: rawIHMImage2
        x:100
        visible: true
        onSourceChanged: console.log(source)
        width: 300
        height: width
        z:1501
    }


    ShaderEffectSource {
        id: shaderCopy
        visible: false
        sourceItem: root.overlay
        anchors.fill: parent
        Rectangle
        {
            color: "blue"
            width: parent.width
            height: 50
        }
        Rectangle
        {
            color: "green"
            width: parent.width
            height: 50
            anchors.bottom: parent.bottom
        }
    }
}