code: private String fullyQualifiedRegistrationDomain() {
      if (job.getRegistrationDomain().endsWith(".")) {
        return job.getRegistrationDomain();
      } else if ("".equals(job.getRegistrationDomain())) {
        return defaultRegistrationDomain;
      } else {
        return job.getRegistrationDomain() + "." + defaultRegistrationDomain;
      }
    }
docs: Given the registration domain in the job, and the default registration domain for the agent,
  figure out what domain we should actually register the job in.
  
  @return The full registration domain.