public function discount(Product $product)
    {
        $discount = $this->money($product);

        if ($product->discount) {
            $discount = $product->discount->product($product);
            $discount = $discount->multiply($product->quantity);
        }

        return $discount;
    }
public function discount(Product $product)
    {
        $discount = $this->money($product);

        if ($product->discount) {
            $discount = $product->discount->product($product);
            $discount = $discount->multiply($product->quantity);
        }

        return $discount;
    }
public function discount ( Product $ product ) { $ discount = $ this -> money ( $ product ) ; if ( $ product -> discount ) { $ discount = $ product -> discount -> product ( $ product ) ; $ discount = $ discount -> multiply ( $ product -> quantity ) ; } return $ discount ; }
Return the discount of the Product

@param Product $product
@return Money
Return the discount of the Product