def get_total(self):
    total = 0
    for item in self.all_items_in_cart:
        total += (RetailItem.get_price(item) * RetailItem.get_units_in_inventory(item))
    return total
def get_total(self):
    total = 0
    for item in self.all_items_in_cart:
        total += (RetailItem.get_price(item) * RetailItem.get_units_in_inventory(item))
    return total