anchor.diff:    int id = cmd["id"];
     outstandingCommands[id] = completer;
     if (verbose) {
  -    print("sending: '${jsonStringify(cmd)}'");
  -  }
  -  vmStream.writeString(jsonStringify(cmd));
  +    print("sending: '${json.stringify(cmd)}'");
  +  }
  +  vmStream.writeString(json.stringify(cmd));
     return completer.future;
   }
   
  
positive.code: }
  
  
  void processVmMessage(String json) {
    var msg = parseJson(json);
    if (msg == null) {
      return;
    }
  
negative.code: // connection port.
  
  import "dart:io";
  import "dart:json" as json;
  import "dart:utf";
  import "dart:async";
  
  
  Map<int, Completer> outstandingCommands;
  