When completed it fires twice

[juarezfranco]

Should this be the expected behavior? code:

onCompleted: (Stream<InstaAssetsExportDetails> stream) {
          print(stream);
          stream.listen((InstaAssetsExportDetails event) async {
            print(event.progress);

output:

flutter: Instance of '_ControllerStream<InstaAssetsExportDetails>'
flutter: 0.0
flutter: 1.0  
flutter: 1.0