public void register(final String authName, final ConsumerDomain cd) throws PEtALSCDKException {
   if (consumers.putIfAbsent(authName, cd) != null) {
     throw new PEtALSCDKException(
         "A consumer partner with the auth-name '"
             + authName
             + "' is already registered for the transporter '"
             + jtl.getId()
             + "'");
   }
 }