code: public static ResourceRecordSet<CNAMEData> cname(String name, Collection<String> cnames) {
      return new CNAMEBuilder().name(name).addAll(cnames).build();
    }
docs: creates cname set of {@link denominator.model.rdata.CNAMEData CNAME} records for the specified
  name.
  
  @param name   ex. {@code www.denominator.io.}
  @param cnames cname values ex. {@code [www1.denominator.io., www2.denominator.io.]}