@NotNull
  protected ChangesGroupingSupport installGroupingSupport() {
    ChangesGroupingSupport result = new ChangesGroupingSupport(myProject, this, false);

    migrateShowFlattenSetting();
    installGroupingSupport(this, result, GROUPING_KEYS, DEFAULT_GROUPING_KEYS);

    return result;
  }
@NotNull
  protected ChangesGroupingSupport installGroupingSupport()