code: public static Calendar load(final String filename) throws IOException, ParserException {
          return new CalendarBuilder().build(Files.newInputStream(Paths.get(filename)));
      }
docs: Loads a calendar from the specified file.
  @param filename the name of the file from which to load calendar data
  @return returns a new calendar instance initialised from the specified file
  @throws IOException occurs when there is an error reading the specified file
  @throws ParserException occurs when the data in the specified file is invalid