public PromotionRule removePromotionRule(PromotionRule promotionRule) {
getPromotionRules().remove(promotionRule);
promotionRule.setPromotion(null);
return promotionRule;
}
public PromotionRule addPromotionRule(PromotionRule promotionRule) {
getPromotionRules().add(promotionRule);
promotionRule.setPromotion(this);
return promotionRule;
}