code: @PreDestroy
      public void shutDown() {
          LOGGER.info("Calling shutdown on ManagerFactory");
  
          if (!configContext.isProvidedSession()) {
              LOGGER.info(format("Closing built Session object %s", rte.session));
              rte.session.close();
          }
          if (!configContext.isProvidedExecutorService()) {
              LOGGER.info(format("Closing built executor service (thread pool) %s", configContext.getExecutorService()));
              configContext.getExecutorService().shutdown();
          }
      }
docs: Shutdown the manager factory and the related session and executor service (if they are created by Achilles).
  If the Java driver Session object and/or the executor service were provided as bootstrap parameter, Achilles
  will <strong>NOT</strong> shut them down. This should be handled externally