     /// - Parameters:
     ///   - session:    The session of the stream task that discovered a better route.
     ///   - streamTask: The stream task that discovered a better route.
-    @available(iOS 9.0, OSX 10.11, *)
     public func urlSession(_ session: URLSession, betterRouteDiscoveredFor streamTask: URLSessionStreamTask) {
         streamTaskOfSessionBetterRouteDiscovered?(streamTask, session)
     }

    /// - Parameters:
    ///   - session:    The session containing the stream task that closed writes.
    ///   - streamTask: The stream task that closed writes.
    @available(iOS 9.0, OSX 10.11, *)
    public func urlSession(_ session: URLSession, writeClosedFor streamTask: URLSessionStreamTask) {
        streamTaskOfSessionWriteClosed?(streamTask, session)
    }

    ///   - streamTask:   The stream task that has been completed.
    ///   - inputStream:  The created input stream. This InputStream object is unopened.
    ///   - outputStream: The created output stream. This OutputStream object is unopened
    public func urlSession(_ session: URLSession, streamTask: URLSessionStreamTask, didBecome inputStream: InputStream, outputStream: OutputStream) {
        streamTaskOfSessionDidBecomeInOutStream?(streamTask, session, inputStream, outputStream)
    }
