public Tuple <long, Hardware, List <ProductSupplier>, List <ProductDetail>, List <PurchaseItem> > GetAllHardwareOfProduct(long productID)
        {
            Hardware hardware = FindById(productID);

            List <ProductSupplier> productSuppliers = repositoryProductSupplier.GetAllProductSuppliersPerProduct(productID);

            List <ProductDetail> productDetails = repositoryProductDetail.GetAllProductDetailsPerProduct(productID);

            List <PurchaseItem> purchaseItems = repositoryPurchaseItem.GetAllPurchaseItemsOfProduct(productID);

            return(new Tuple <long, Hardware, List <ProductSupplier>, List <ProductDetail>, List <PurchaseItem> >(productID, hardware, productSuppliers, productDetails, purchaseItems));
        }