@available(iOS 10.0, *)
open class UNNotificationServiceExtension : NSObject {
// Call contentHandler with the modified notification content to deliver. If the handler is not called before the service's time expires then the unmodified notification will be delivered.
// You are expected to override this method to implement push notification modification.
open func didReceive(_ request: UNNotificationRequest, withContentHandler contentHandler:
@escaping (UNNotificationContent) -> Void)
// Will be called just before this extension is terminated by the system. You may choose whether to override this method.
open func serviceExtensionTimeWillExpire()
}