code: private static GeneralNames getFullNames(X500Name issuer, RDN rdn)
          throws IOException
      {
          List<RDN> rdns = new ArrayList<>(issuer.rdns());
          rdns.add(rdn);
          X500Name fullName = new X500Name(rdns.toArray(new RDN[0]));
          GeneralNames fullNames = new GeneralNames();
          fullNames.add(new GeneralName(fullName));
          return fullNames;
      }
docs: Append relative name to the issuer name and return a new
  GeneralNames object.