docs: public PeriodFormatterBuilder appendPrefix(String[] regularExpressions, String[] prefixes) {
          if (regularExpressions == null || prefixes == null ||
                  regularExpressions.length < 1 || regularExpressions.length != prefixes.length) {
              throw new IllegalArgumentException();
          }
          return appendPrefix(new RegExAffix(regularExpressions, prefixes));
      }