$cart->validateStock()

Makes sure no product is in the list more often than its stock allows

$cart->validateStock(null|Wagnerwagner\Merx\ProductPage $page = null): Wagnerwagner\Merx\ProductList

Parameters

Name	Type	Default
`$page`	`null` or `ProductPage`	`null`

Type	Description
`Exception`	error.merx.cart.soldOut when a product is sold out
`Exception`	error.merx.cart.stock when a product exceeds its stock

The lines of a product are added up first, so a product with one line per
name cannot get past its stock one name at a time.