Cart/Entity/CartItem.php
public function setSale(Common\SaleInterface $sale = null)
    {
        $sale && $this->assertSaleClass($sale);

        $this->setCart($sale);

        return $this;
    }
public function setSale(Common\SaleInterface $sale = null)
    {
        $sale && $this->assertSaleClass($sale);

        $this->setCart($sale);

        return $this;
    }
@inheritdoc

@param Model\CartInterface $sale