docs: public static TsurgeonPattern parseOperation(String operationString) {
      try {
        TsurgeonParser parser =
          new TsurgeonParser(new StringReader(operationString + "\n"));
        return new TsurgeonPatternRoot(new TsurgeonPattern[] {parser.Root()} );
      } catch(ParseException e) {
        throw new TsurgeonParseException("Error parsing Tsurgeon expression: " +
                                         operationString, e);
      } catch(TokenMgrError e) {
        throw new TsurgeonParseException("Error parsing Tsurgeon expression: " +
                                         operationString, e);
      }
    }