test.dart

    ObservableList<Peer> sub = toObservable(server.peers) as ObservableList<Peer>;
    sub.changes.listen((l) {
      print('Changes');
    });
    sub.listChanges.listen((l) {
      print('List');
    });

    server.peers.add(new Peer());
    new Timer.periodic(new Duration(seconds: 5), (t) {
      server.peers.add(new Peer());
      print('Timer');
    }); // Print 'Timer' but not 'Changes' nor 'List'