@NotNull
  private ActionToolbar createToolbar() {
    final DefaultActionGroup actionGroup = new DefaultActionGroup();
    actionGroup.add(new MyRefreshAction(myTree));
    if (isToShowAutoScrollButton()) {
      actionGroup.add(myAutoScrollToSourceHandler.createToggleAction());
    }

    if (isToShowPreviewButton()) {
      actionGroup.add(new ToggleAction(UsageViewBundle.message("preview.usages.action.text"),
                                       LangBundle.message("action.preview.description"), AllIcons.Actions.PreviewDetails) {
        @Override
        public boolean isSelected(@NotNull AnActionEvent e) {
          return isPreview();
        }

        @Override
        public @NotNull ActionUpdateThread getActionUpdateThread() {
          return ActionUpdateThread.EDT;
        }

        @Override
        public void setSelected(@NotNull AnActionEvent e, boolean state) {
          setPreview(state);
          layoutPanel();
        }
      });
    }

    ActionManager actionManager = ActionManager.getInstance();
    actionGroup.add(actionManager.getAction(IdeActions.ACTION_EXPAND_ALL));
    actionGroup.add(actionManager.getAction(IdeActions.ACTION_COLLAPSE_ALL));
    actionGroup.addSeparator();
    myProvider.registerExtraPanelActions(actionGroup, myBuilder);
    actionGroup.add(CommonActionsManager.getInstance().createExportToTextFileAction(new SliceToTextFileExporter(myBuilder, UsageViewSettings.getInstance())));

    //actionGroup.add(new ContextHelpAction(HELP_ID));

    return ActionManager.getInstance().createActionToolbar(ActionPlaces.TYPE_HIERARCHY_VIEW_TOOLBAR, actionGroup, false);
  }
@NotNull
  private ActionToolbar createToolbar()