Cart/Entity/CartItem.php
protected function assertSaleClass(Common\SaleInterface $sale)
    {
        if (!$sale instanceof Model\CartInterface) {
            throw new InvalidArgumentException("Expected instance of " . Model\CartInterface::class);
        }
    }
protected function assertSaleClass(Common\SaleInterface $sale)
    {
        if (!$sale instanceof Model\CartInterface) {
            throw new InvalidArgumentException("Expected instance of " . Model\CartInterface::class);
        }
    }
Asserts that the given sale is an instance of the expected class.

@param Common\SaleInterface $sale