CompositeSubscription required but not included in example.

[Bradley Baago]

"var compositeSubscription = new CompositeSubscription();" in https://github.com/apptreesoftware/flutter_google_map_view/blob/master/example/lib/main.dart requires https://pub.dartlang.org/packages/composite_subscription but it does not include it. Furthermore that plugin no longer works with the newest flutter sdk. Trying to compile it anyway results in "Error: Method not found: 'CompositeSubscription'.".