code: @PostConstruct
    public void initializeDiscountRules() {
      List<DiscountRuleEntry> rules = rulesDAO.findAllDiscountRuleEntries();
      if ((rules == null) || (rules.size() == 0)) {
        log.info("Creating initial sample discount rules: ...");
        rulesDAO.save(new DiscountRuleEntry("Small orders", 0, 500, 5));
        rulesDAO.save(new DiscountRuleEntry("Medium orders", 500, 1000, 7));
        rulesDAO.save(new DiscountRuleEntry("Big orders", 1000, 5000, 10));
      }
    }
docs: /*
  If no discount rules are present in the database, we create some initial ones