/**
* If the cart's shipping amount is not defined, then put an empty Money
* value
*
* @param CartInterface $cart Cart
*/
public function validateEmptyShippingAmount(CartInterface $cart)
{
$shippingAmount = $cart->getShippingAmount();
if (!$shippingAmount instanceof MoneyInterface) {
$cart->setShippingAmount($this->emptyMoneyWrapper->get());
}
}
