 
   init<U>(qos: qos_class_t = QOS_CLASS_UNSPECIFIED, source: Deferred<U>, transform: (U) -> Result<T>)
   {
-    super.init(source.queue)
+    super.init(queue: source.queue)
 
     source.notify(qos: qos) {
       result in


  init<U>(qos: qos_class_t = QOS_CLASS_UNSPECIFIED, source: Deferred<U>, transform: (U) -> Deferred<T>)
  {
    super.init(source.queue)

    source.notify(qos: qos) {
      result in


  init<U>(qos: qos_class_t = QOS_CLASS_UNSPECIFIED, source: Deferred<U>, transform: (U) throws -> T)
  {
    super.init(queue: source.queue)

    source.notify(qos: qos) {
      result in
