public function addShippingAddress(Address $shippingAddress)
    {
        if ($this->shipping == null) {
            $this->shipping = [];
        }

        $this->shipping[] = $shippingAddress;

        return $this;
    }
public function addShippingAddress(Address $shippingAddress)
    {
        if ($this->shipping == null) {
            $this->shipping = [];
        }

        $this->shipping[] = $shippingAddress;

        return $this;
    }
@param Address $shippingAddress

@return Cart