code: public static Range valueOf(final String value) {
          final Optional<Integer[]> vals = parse(value);
          if (vals.isPresent()) {
              return new Range(vals.get()[0], vals.get()[1]);
          }
          return null;
      }
docs: Get a Range object from a header value
  @param value the header value
  @return the Range object or null if the value is not parseable