code: public static String generateRegId(final String domainCreationDate, final String reverseDomainName) {
          return generateRegId(domainCreationDate, reverseDomainName, null);
      }
docs: Generate RegId.
  
  @param domainCreationDate
  the date at which the entity creating the regid first owned the domain that is also used in the regid
  in year-month format; e.g. 2010-04
  @param reverseDomainName
  the domain of the entity, in reverse order; e.g. com.labs64
  @return generated RegId