             // add headding item
             let headdingItem = NSMenuItem()
             headdingItem.title = "<Outline Menu>".localized
-            headdingItem.representedObject = NSRange(location: 0, length: 0)
+            headdingItem.representedObject = NSRange(0..<0)
             menu.addItem(headdingItem)
             
             // add outline items

        
        guard let popUp = self.outlineMenu, self.canSelectPrevItem else { return }
        
        let index = stride(from: popUp.indexOfSelectedItem - 1, to: 0, by: -1)
            .first { popUp.item(at: $0)!.representedObject != nil } ?? 0
        
        popUp.menu!.performActionForItem(at: index)
    }

        
        guard let popUp = self.outlineMenu, self.canSelectNextItem else { return }
        
        let index = popUp.itemArray[(popUp.indexOfSelectedItem + 1)...]
            .firstIndex { $0.representedObject != nil }
        
        if let index = index {
            popUp.menu!.performActionForItem(at: index)
