anchor.diff:                  let key = lParam |> Marshal.ReadInt32 |> enum<Keys> 
                   match form.GetFocusedControl () with
                   | :? ToolStripDropDown
  +                // | :? ToolStripComboBox wtf?
                   | :? TextBox
                   | :? SymbolicTextBox -> handleKeyboardInput key true form !Globals.WorldRef
                   | _ -> handleKeyboardInput key false form !Globals.WorldRef
  
positive.code:             else deselectEntity form world
          | _ -> ()
  
      let private selectLayer (form : GaiaForm) layer world =
          let layerTds = { DescribedLayer = layer; Form = form }
          Globals.WorldRef := world // must be set for property grid
          form.layerPropertyGrid.SelectedObject <- layerTds
  
negative.code:             form.entityTreeView.Nodes.Add treeNode |> ignore
          let selectedLayer = (World.getUserValue world).SelectedLayer
          for entity in World.getEntities selectedLayer world do
              addEntityTreeViewNode entity form world
          restoreExpansionState form.entityTreeView treeState
          setEntityTreeViewSelectionToEntityPropertyGridSelection form
  
  