anchor.diff:  // Copyright 2014 The Flutter Authors. All rights reserved.
   // Use of this source code is governed by a BSD-style license that can be
   // found in the LICENSE file.
  -
  -// @dart = 2.8
   
   import 'dart:async';
   
  
positive.code:     int hostPort,
      bool ipv6,
      bool disableServiceAuthCodes, {
      @required Logger logger,
    }) async {
      final Uri ddsUri = Uri(
        scheme: 'http',
  
negative.code:           enableAuthCodes: !disableServiceAuthCodes,
            ipv6: ipv6,
          );
        unawaited(_ddsInstance?.done.whenComplete(() {
          if (!_completer.isCompleted) {
            _completer.complete();
          }
        }));
        logger.printTrace('DDS is listening at ${_ddsInstance?.uri}.');
      } on dds.DartDevelopmentServiceException catch (e) {
        logger.printTrace('Warning: Failed to start DDS: ${e.message}');
        if (e.errorCode == dds.DartDevelopmentServiceException.existingDdsInstanceError) {
  