Comment 1 for bug 1560004

In Scrollbar, UbuntuListView and ExpandableColumns tests the issue is the same,
"Type Error" when trying to do either
var sceneThumbX = thumb.mapToItem(column).x

or
fuzzyCompare(ubuntuListView.mapFromItem(item).y, item.collapsedHeight, .5);

or
compare(expandablesColumn.mapFromItem(item).y, item.collapsedHeight);