   {
     WaitQueue.dealloc(waiters)
   }
+
+  // MARK: initialize with a closure
 
   /// Initialize with a computation task to be performed in the background, at the current quality of service
   ///

  private var currentState: Int32
  private var waiters: UnsafeMutablePointer<Waiter> = nil

  // MARK: Initializers

  private init()
  {

    currentState = DeferredState.Executing.rawValue
    dispatch_async(queue, block)
  }

  // MARK: initialize with a result, value or error

  /// Initialize to an already determined state
  ///
