public List<Exprent> getAllExprents(boolean recursive) {
    List<Exprent> lst = getAllExprents();
    if (recursive) {
      for (int i = lst.size() - 1; i >= 0; i--) {
        lst.addAll(lst.get(i).getAllExprents(true));
      }
    }
    return lst;
  }
public List<Exprent> getAllExprents(boolean recursive)