@Nullable
  public static FoldRegion addFolding(@NotNull EditorEx editor, int start, int end, boolean expanded) {
    DocumentEx document = editor.getDocument();
    final int startOffset = document.getLineStartOffset(start);
    final int endOffset = document.getLineEndOffset(end - 1);

    FoldRegion region = editor.getFoldingModel().addFoldRegion(startOffset, endOffset, PLACEHOLDER);
    if (region != null) {
      region.setExpanded(expanded);
      region.setInnerHighlightersMuted(true);
      FoldingModelImpl.hideGutterRendererForCollapsedRegion(region);
    }
    return region;
  }
@Nullable
  public static FoldRegion addFolding(@NotNull EditorEx editor, int start, int end, boolean expanded)