get
fun getProductWith(productId: String, phaseId: String, completionHandler: (SubscriptionPhase?, NetworkingError?) -> Unit)
Retrieves a specific phase on a product by its identifier and delivers the result via a callback.
Parameters
product
The unique identifier of the product that owns the phase.
phase
The unique identifier of the phase to retrieve.
completion
Invoked with the matching SubscriptionPhase on success, or a NetworkingError on failure.