anchor.diff:      bool enableObservatory: false,
       bool startPaused: false,
       int observatoryPort,
  +    int serverPort,
     }) {
       assert(executable != null); // Please provide the path to the shell in the SKY_SHELL environment variable.
       assert(!startPaused || enableObservatory);
  
positive.code: 
  void main() {
    print('$_kStartTimeoutTimerMessage');
    String server = Uri.decodeComponent('$encodedWebsocketUrl');
    StreamChannel channel = serializeSuite(() {
      catchIsolateErrors();
      return test.main;
  
negative.code:     return tempBundleDirectory.path;
    }
  
    String _getWebSocketUrl() {
      return host.type == InternetAddressType.IP_V4
          ? 'ws://${host.address}'
          : 'ws://[${host.address}]';
    }
  
    String _generateTestMain({
  