public ProductSkuStock saveOrUpdateStock(ProductSkuStock productSkuStock) {
if (productSkuStock.getId() != null) {
if(em.contains(productSkuStock)){
em.refresh(productSkuStock);
}
ProductSkuStock mergedProductSkuStock = em.merge(productSkuStock);
em.flush();
return mergedProductSkuStock;
} else {
em.persist(productSkuStock);
return productSkuStock;