anchor.diff:    /// [Stream.listen] method.
     StreamSubscription<T> listen(void onData(T event), {Function onError, void onDone(), bool cancelOnError});
   
  -  Reactable map(convert(T event)) => new _ReactableAsStream(this).map(convert);
  +  Reactable map(convert(T event)) => new EventStream(new _ReactableAsStream(this).map(convert));
   
     Future<T> reduce(T combine(T previous, T element)) => new _ReactableAsStream(this).reduce(combine);
   
  
positive.code:     ));
    }
  
    EventStream flatMapLatest(Stream convert(T event)) {
      return new _ReactableAsStream(new _FlatMapLatestReactable(this, convert));
    }
  
    /// Returns a new stream that contains events from this stream until the [future]
    /// completes.
    Reactable<T> takeUntil(Future future) => new _TakeUntilReactable(this, future);
  
    Reactable<T> takeWhile(bool test(T element)) => new _ReactableAsStream(this).takeWhile(test);
  
    /// Returns a new reactable that forwards events when the last value for [toggle] is
    /// `true`.
  
negative.code:   /// Delays the delivery of each non-error event from this stream by the given [duration].
    Reactable<T> delay(Duration duration) => new _DelayReactable(this, duration);
  
    Reactable<T> distinct([bool equals(T previous, T next)]) => new EventStream(
        new _ReactableAsStream(this).distinct(equals));
  
    Future drain([futureValue]) => new _ReactableAsStream(this).drain(futureValue);
  
    Future<bool> every(bool test(T element)) => new _ReactableAsStream(this).every(test);
  
    Reactable expand(Iterable convert(T value)) => new EventStream(new _ReactableAsStream(this).expand(convert));
  
    Future<dynamic> firstWhere(bool test(T element), {Object defaultValue()}) =>
        new _ReactableAsStream(this).firstWhere(test, defaultValue: defaultValue);
  