code: @Override
    public void stop() throws IOException {
      if (jettyServer != null) {
        try {
          jettyServer.stop();
        } catch (IOException e) {
          throw e;
        } catch (Exception e) {
          throw new IOException(e);
        }
      }
    }
docs: Stop Jetty server after it has been started.
  This is unlikely to ever be called by H2O until H2O supports graceful shutdown.
  
  @throws Exception -