code: public void stop() {
      LOG.info("Stopping {}", getClass().getSimpleName());
      if (txService == null) {
        return;
      }
      try {
        if (txService.isRunning()) {
          txService.stopAndWait();
        }
      } catch (Throwable e) {
        LOG.error("Failed to shutdown transaction service.", e);
        // because shutdown hooks execute concurrently, the logger may be closed already: thus also print it.
        System.err.println("Failed to shutdown transaction service: " + e.getMessage());
        e.printStackTrace(System.err);
      }
    }
docs: Invoked by jsvc to stop the program.