public function load(ObjectManager $manager)
{
$ruleFactory = $this->getFactory('rule');
$ruleLowCost = $ruleFactory->create()->setName('Importe inferior a 300€')->setExpression('cart.getPurchasableAmount().isLessThan(money(300))');
$manager->persist($ruleLowCost);
$ruleFewItems = $ruleFactory->create()->setName('Menos de 3 productos')->setExpression('cart.getQuantity() < 3');
$manager->persist($ruleFewItems);
$ruleDiscount = $ruleFactory->create()->setName('Superior a 300€ y menos de 3 productos')->setExpression('not rule("Importe inferior a 300€") and rule("Menos de 3 productos")');
$manager->persist($ruleDiscount);
$this->setReference('rule-big-spender', $ruleDiscount);
$manager->flush();
}