code: public JobService getJobService() {
      if (service == null) {
        try {
          Registry registry = LocateRegistry.getRegistry(host, JdcpUtil.DEFAULT_PORT);
          AuthenticationService auth = (AuthenticationService) registry.lookup("AuthenticationService");
          service = auth.authenticate(username, password, JdcpUtil.PROTOCOL_VERSION_ID);
        } catch (NotBoundException e) {
          System.err.println("Job service not found at remote host.");
          System.exit(1);
        } catch (RemoteException e) {
          System.err.println("Could not connect to job service.");
          e.printStackTrace();
          System.exit(1);
        } catch (LoginException e) {
          System.err.println("Login failed.");
          System.exit(1);
        } catch (ProtocolVersionException e) {
          System.err.println("This client is incompatible with the remote server.  Please update the client and try again.");
          System.exit(1);
        }
      }
      return service;
    }
docs: Gets the <code>JobService</code> to use for this client session.
  @return the <code>JobService</code> to use for this client session