anchor.diff:  
   
   void quitShell() {
  -  vmStream.close();
  +  streamSubscription.cancel();
     vmSock.close();
     stdin.close();
   }
  
positive.code:   if (verbose) {
      print("sending: '${json.stringify(cmd)}'");
    }
    vmStream.writeString(json.stringify(cmd));
    return completer.future;
  }
  
  
negative.code:   if (arguments.length > 0) {
      arguments = <String>['--debug', '--verbose_debug']..addAll(arguments);
      Process.start(options.executable, arguments).then((Process process) {
        process.stdin.close();
        process.exitCode.then((int exitCode) {
          print('${arguments.join(" ")} exited with $exitCode');
        });
        debuggerMain();
      });
    } else {
  