docs: public MutablePeriod parseMutablePeriod(String text) {
          checkParser();
          
          MutablePeriod period = new MutablePeriod(0, iParseType);
          int newPos = getParser().parseInto(period, text, 0, iLocale);
          if (newPos >= 0) {
              if (newPos >= text.length()) {
                  return period;
              }
          } else {
              newPos = ~newPos;
          }
          throw new IllegalArgumentException(FormatUtils.createErrorMessage(text, newPos));
      }