docs: @Override
    public Tree readTree() throws IOException {
      Tree tr = super.readTree();
      while (tr != null && tr.firstChild().value().equals("FRAG")) {
  //      if (pw != null) {
  //        pw.println("Discarding Tree:");
  //        tr.pennPrint(pw);
  //      }
        tr = super.readTree();
      }
      return tr;
    }