@Override
  protected @NotNull List<TextEditorHolder> createEditorHolders(@NotNull EditorHolderFactory<TextEditorHolder> factory) {
    List<TextEditorHolder> holders = super.createEditorHolders(factory);
    ThreeSide.BASE.select(holders).getEditor().putUserData(DiffUserDataKeys.MERGE_EDITOR_FLAG, true);
    return holders;
  }
@Override
  protected @NotNull List<TextEditorHolder> createEditorHolders(@NotNull EditorHolderFactory<TextEditorHolder> factory)