private @Nullable Runnable updateFoldRegions(@NotNull Editor editor, boolean applyDefaultState, boolean quick) {
    PsiFile file = PsiDocumentManager.getInstance(myProject).getPsiFile(editor.getDocument());
    return file == null ? null : FoldingUpdate.updateFoldRegions(editor, file, applyDefaultState, quick);
  }
private @Nullable Runnable updateFoldRegions(@NotNull Editor editor, boolean applyDefaultState, boolean quick)