StreamController not resolving onDone handler when using a StreamTransformer

main.dart

import 'dart:async';

void main(List<String> arguments) {
  var c = StreamController();
  var s = c.stream
      .transform(StreamTransformer.fromHandlers(handleData: (data, sink) {
    sink.add(data);
  }, handleDone: (sink) => sink.close()));

  s.listen((event) {
    print(event.toString());
  }, onDone: () {
    print('Subscription is done');
  });

  c.add('An Event');
  c.close();
}