anchor.diff:  
   class AltitudePage extends Page {
     final List widgets;
  +  final List props;
     final AltitudeWidget altitude;
   
     int _selected = 0;
  
positive.code:         props['nav1-radial']))
      ..add(new NavRadioPage('NAV2', props['nav2-actual'], props['nav2-standby'],
          props['nav2-radial']))
      ..add(new AltitudePage());
  
    var send = await RawDatagramSocket.bind(InternetAddress.ANY_IP_V4, 1236);
    props.onUpdate.listen((update) {
  
negative.code: import 'package:logging/logging.dart';
  import 'package:serial_port/serial_port.dart';
  
  Stopwatch _start = new Stopwatch()..start();
  
  Logger log = new Logger('main');
  
  main(List<String> args) async {
    Logger.root.level = Level.INFO;
    Logger.root.onRecord.listen((LogRecord rec) {
      print('${_start.elapsed}: ${rec.level.name}: [${rec.loggerName}] '
          '${rec.message}');
    });
  
    var port = args.isEmpty ? "COM3" : args.first;
  