code: public static ResourceRecordSet<CERTData> cert(String name, String certdata) {
      return new CERTBuilder().name(name).add(certdata).build();
    }
docs: creates cert set of {@link denominator.model.rdata.CERTData CERT} records for the specified
  name and ttl.
  
  @param name     ex. {@code denominator.io.}
  @param certdata {@code 12345 1 1 B33F}