/** @param module */
  public NavigationModuleTreeUI(ModuleNavigationModule module) {
    super(module);

    verticalPanel = new VerticalPanel();
    verticalPanel.ensureDebugId(ModuleNavigationModule.MODULE_ID);

    final NavigationTreeModel navigationTreeModel = new NavigationTreeModel();
    CellTree cellTree = new CellTree(navigationTreeModel, null);

    verticalPanel.add(cellTree);

    navigationTreeModel.setNavigationTreeModel(module.getNavigationTreeRoots());
  }