code: public Component copy() throws ParseException, IOException, URISyntaxException {
          final VTimeZone copy = (VTimeZone) super.copy();
          copy.observances = new ComponentList<Observance>(observances);
          return copy;
      }
docs: Overrides default copy method to add support for copying observance sub-components.
  @return a copy of the instance
  @throws ParseException where an error occurs parsing data
  @throws IOException where an error occurs reading data
  @throws URISyntaxException where an invalid URI is encountered
  @see net.fortuna.ical4j.model.Component#copy()