anchor.diff:      if (!controller.isClosed) controller.add(event);
     }
   
  -  /// Merges two stream into one, the merged stream will forward any events and errors received from the input
  -  /// streams. The merged stream will complete if:
  -  /// * both input streams have completed
  -  /// * [closeOnError] flag is set to true and an error is received
  +  /**
  +   * Merges two stream into one, the merged stream will forward any elements and errors received from the input streams.
  +   *
  +   * The merged stream will complete if:
  +   *
  +   * * both input streams have completed
  +   * * [closeOnError] flag is set to true and an error is received
  +   */
     static Stream merge(Stream stream1, Stream stream2, { bool closeOnError : false, bool sync : false }) {
       var controller = new StreamController.broadcast(sync : sync);
       var completer1 = new Completer();
  
positive.code:     return controller.stream;
    }
  
    /// Merges two streams into one stream by using the selector function whenever one of the streams produces an event.
    /// The merged stream will complete if:
    /// * both input streams have completed
    /// * [closeOnError] flag is set to true and an error is received
    static Stream combineLatest(Stream stream1, Stream stream2, dynamic selector(dynamic item1, dynamic item2), { bool closeOnError : false, bool sync : false }) {
      var controller = new StreamController.broadcast(sync : sync);
      var completer1 = new Completer();
  
negative.code:     return controller.stream;
    }
  
    /**
     * Creates a new stream who stops the flow of elements produced by the input stream until no new element has been produced by the input stream after the specified duration.
     *
     * The throttled stream will complete if:
     *
     * * the input stream has completed and the any throttled message has been delivered
     * * [closeOnError] flag is set to true and an error is received
     */
    static Stream throttle(Stream input, Duration duration, { bool closeOnError : false, bool sync : false }) {
      var controller = new StreamController.broadcast(sync : sync);
      var onError    = _getOnErrorHandler(controller, closeOnError);
  