@NotNull
  protected List<ArrangementGroupingRule> cloneGroupings() {
    final ArrayList<ArrangementGroupingRule> groupings = new ArrayList<>();
    for (ArrangementGroupingRule grouping : myGroupings) {
      groupings.add(grouping.clone());
    }
    return groupings;
  }
@NotNull
  protected List<ArrangementGroupingRule> cloneGroupings()