New SKStoreFront, it lets us know what country the user is from, we can use it to sell targeted things to that user.
if let sf = SKPaymentQueue.default().storefront {
...
}It can be nil (the presenter didn’t say how/why).
Use this to observe changes (e.g. when the user change store/account)
//MARK: - SKPaymentTransactionObserver methods
func paymentQueueDidChangeStorefront(_ queue: SKPaymentQueue) {
...
}