code: public static ResourceRecordSet<MXData> mx(String name, String mxdata) {
      return new MXBuilder().name(name).add(mxdata).build();
    }
docs: creates mx set of {@link denominator.model.rdata.MXData MX} records for the specified name and
  ttl.
  
  @param name   ex. {@code denominator.io.}
  @param mxdata {@code 1 mx1.denominator.io.}