In iOS land it's done w/ a delegate of the NSURLSessionTask:
https://github.com/aerogear/aerogear-push-ios-registration/blob/master/push-sdk/AGDeviceRegistration.m#L136-L153
In iOS land it's done w/ a delegate of the NSURLSessionTask:
https://github.com/aerogear/aerogear-push-ios-registration/blob/master/push-sdk/AGDeviceRegistration.m#L136-L153