protected void collectPopupActions(@Nullable List<? extends AnAction> viewerActions) {
    myPopupActionGroup.removeAll();

    DiffUtil.addActionBlock(myPopupActionGroup, new MyChangeDiffToolActionGroup());

    DiffUtil.addActionBlock(myPopupActionGroup, viewerActions);
  }
protected void collectPopupActions(@Nullable List<? extends AnAction> viewerActions)