anchor.diff:          refreshOverlayComboBox form Globals.World
           refreshCreateComboBox form Globals.World
           refreshEntityTreeView form Globals.World
  +        refreshGroupTabs form Globals.World
           refreshHierarchyTreeView form Globals.World
  -        refreshGroupTabs form Globals.World
           selectGroup defaultGroup form Globals.World
           form.tickingButton.CheckState <- CheckState.Unchecked
           form.songPlaybackButton.CheckState <- if World.getMasterSongVolume world = 0.0f then CheckState.Unchecked else CheckState.Checked
  
positive.code:             let world = updateEditorState (fun editorState -> { editorState with DragCameraState = DragCameraNone }) world
              (Resolve, world)
          | DragCameraNone -> (Resolve, world)
  
      let private monitorEntityEvents (group : Group) form world =
          let world = World.monitor (handleNuChangeParentNodeOpt form) (Events.Change Property? ParentNodeOpt --> group --> Events.Wildcard) group world
  
negative.code:         addHierarchyTreeEntityNode entity form world
          (Cascade, world)
  
      let private handleNuGroupRegister (form : GaiaForm) evt world =
          refreshGroupTabs form world
          refreshHierarchyTreeView form world
          (Cascade, world)
  
      let private handleNuGroupUnregistering (form : GaiaForm) evt world =
          refreshGroupTabs form world
          refreshHierarchyTreeView form world
          (Cascade, world)
  
      let private handleNuEntityRegister (form : GaiaForm) evt world =
          let entity = Entity (atoa evt.Publisher.SimulantAddress)
          addEntityTreeViewNode entity form world
  