title: How do I use delegates within Xamarin (specifically UNUserNotificationCenterDelegate)
body: <p>I need to use the iOS 10 features in <a href="https://developer.apple.com/reference/usernotifications/unusernotificationcenterdelegate" rel="nofollow noreferrer">UNUserNotificationCenterDelegate</a>.  How can I implement this delegate in c# / Xamarin?</p>