anchor.diff:  
     Future<T> _callMethod<T>(String method, [Map<String, dynamic> params]) {
       final id = '${_nextRequestId++}';
  -    final json = jsonEncode({'id': id, 'method': method, 'params': params});
  +    final json = jsonEncode({
  +      'jsonrpc': '2.0',
  +      'id': id,
  +      'method': method,
  +      'params': params,
  +    });
       final completer = Completer<T>();
       _completers[id] = completer;
       sseClient.sink.add(json);
  
positive.code: 
    static Future<DevToolsServerConnection> connect() async {
      final baseUri = Uri.base;
      final uri = Uri(
          scheme: baseUri.scheme,
          host: baseUri.host,
          port: baseUri.port,
          path: '/api/ping');
  
      try {
        // ignore: unused_local_variable
  
negative.code:       return null;
      }
  
      final sseUri = Uri(pathSegments: [
        '', // Leading '/'
        ...baseUriPathSegments,
        'api',
        'sse'
      ]);
      final client = SseClient(sseUri.toString());
      return DevToolsServerConnection._(client);
    }
  
  