I'd like to create a Menu in QML application that has other Menus depending on some Model. When I use Instantiator for that, items which are being created are parented to the Instantiator itself and when adding them to top-level Menu, it complains about `__parentMenu` being null

Qt Code: 
  1. Menu {
  2.         title: qsTr("Top-Level Menu")
  3.         id: topMenu
  4.  
  5.         Instantiator {
  6.             model: aTopLevelModel
  7.             onObjectAdded: topMenu.insertItem( index, object )
  8.             onObjectRemoved: topMenu.removeItem( object )
  9.  
  10.             delegate: Menu {
  11.                 id: innerMenu
  12.                 title: qsTr("Inner Menu")
  13.  
  14.                 Instantiator {
  15.                     model: aTopLevelModel.getInnerModel(index)
  16.                     onObjectAdded: innerMenu.insertItem( index, object )
  17.                     onObjectRemoved: innerMenu.removeItem( object )
  18.  
  19.                     delegate: MenuItem {
  20.                         text: qsTr("Menu action!")
  21.                         onTriggered: {
  22.                             console.log("Action of inner menu")
  23.                         }
  24.                     }
  25.                 }
  26.             }
  27.         }
  28.     }
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The warning I'm observing is:
Qt Code: 
  1. Menu.qml:149: TypeError: Cannot read property '__contentItem' of null
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Where the line 149 is
Qt Code: 
  1. property var __parentContentItem: __parentMenu.__contentItem
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How can I overcome this Warning being produced?

Qt version is 5.5.1. This behavior is observed undre OS X and Windows versions of Qt.