anchor.diff:              match treeView with
               | Some(treeView) -> treeView :> Widget
               | None -> 
  +                let treeStore = new TreeStore(typedefof<obj>)
  +                let padTreeView = new PadTreeView(treeStore)
  +
                   let setCellIcon (_) (cellRenderer : CellRenderer) (treeModel : TreeModel) (iter : TreeIter) = 
                       let pixRenderer = cellRenderer :?> CellRendererImage
                       let item = treeModel.GetValue(iter, 0) :?> FSharpNavigationDeclarationItem
  
positive.code:                        treeStore.Clear()
                         let toplevel = ast.GetNavigationItems()
                         for item in toplevel do
                             printfn "%s %s" item.Declaration.Name (string item.Declaration.Kind)
                             let iter = treeStore.AppendValues(item.Declaration)
                             for nested in item.Nested do
                                 treeStore.AppendValues(iter, [| nested |]) |> ignore
                                 printfn "nested - %s %s" nested.Name (string nested.Kind)
                         treeView.ExpandAll()
                     | None -> ())
          Gdk.Threads.Leave()
  
negative.code:                 padTreeView.AppendColumn treeCol |> ignore
                  padTreeView.HeadersVisible <- true
                  //padTreeView.Realized.Add refillTree
                  padTreeView.Selection.Changed.Subscribe(fun _ -> jumpToDeclaration false) |> ignore
                  padTreeView.RowActivated.Subscribe(fun _ -> jumpToDeclaration true) |> ignore
  
                  let sw = new CompactScrolledWindow()
  //                padTreeView.Model <- treeStore
  