public function delivery(Product $product)
    {
        $delivery = $product->delivery->multiply($product->quantity);

        return $delivery;
    }
public function delivery(Product $product)
    {
        $delivery = $product->delivery->multiply($product->quantity);

        return $delivery;
    }
public function delivery ( Product $ product ) { $ delivery = $ product -> delivery -> multiply ( $ product -> quantity ) ; return $ delivery ; }
Return the delivery charge of the Product

@param Product $product
@return Money
Return the delivery charge of the Product