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:                     let renderer = cellRenderer :?> CellRendererText
                      let item = treeModel.GetValue(iter, 0) :?> FSharpNavigationDeclarationItem
                      renderer.Text <- item.Name
                  let jumpToDeclaration _ =
                      let iter : TreeIter ref = ref Unchecked.defaultof<_>
                      match padTreeView.Selection.GetSelected(iter) with
                      | true -> let node = padTreeView.Model.GetValue(!iter, 0) :?> FSharpNavigationDeclarationItem
                                x.Editor.CaretLine <- node.Range.StartLine
                                x.Editor.CaretColumn <- node.Range.StartColumn
                                ()
                      | false -> ()
  
                      () 
  //                let refillTree _ = 
  //                    DispatchService.AssertGuiThread()
  //                    Gdk.Threads.Enter()
  //                    treeStore.AppendValues("23") |> ignore
  //                    Gdk.Threads.Leave()
                  
                  treeView <- Some padTreeView
  
                  let pixRenderer = new CellRendererImage()
  