     private let _renewSubscriptionSessionManager = AFHTTPSessionManager()
     private let _unsubscribeSessionManager = AFHTTPSessionManager()
     private let _defaultSubscriptionTimeout: Int = 300
-    private var _backupSubscriptions = [Subscription]()
     private var _eventCallBackURL: NSURL? {
         let wifiInterface = "en0"
         if let address = getIFAddresses()[wifiInterface] {


internal func ==(lhs: UPnPEventSubscriptionManager.Subscription, rhs: UPnPEventSubscriptionManager.Subscription) -> Bool {
    return lhs.subscriptionID == rhs.subscriptionID
}

extension AFHTTPSessionManager {

                return
            }
            
            let now = NSDate()
            let expiration = now.dateByAddingTimeInterval(NSTimeInterval(response.timeout))
            
            let subscription = Subscription(subscriptionID: response.subscriptionID, expiration: expiration, subscriber: subscriber, eventURLString: eventURL.absoluteString!, manager: self)
            
            DDLogInfo("Successfully subscribed with timeout: \(response.timeout/60) mins: \(subscription)")
            
            self.add(subscription: subscription, completion: { () -> Void in
                if let completion = completion {
                    completion(result: .Success(subscription))
                }
            })
            }, failure: { (task: NSURLSessionDataTask?, error: NSError) -> Void in
                DDLogError("Failed to subscribe to event URL: \(eventURL.absoluteString!)\nerror: \(error)")
                if let completion = completion {
                    completion(result: .Failure(error))
                }
