anchor.diff:    // off by at max (#workers - 1).
     var p = spawnFunction(worker);
     workerPorts.add(p);
  -  p.send(new Message(Message.WORK, [sharedEnv, files]), port);
  +  p.send(new Message(Message.WORK, [sharedEnv, files]), port.toSendPort());
   
     return 0;
   }
  
positive.code:     env.output = new File(env.output).openWrite();
    }
  
    if (args["pretty-print"] &&
        args["lcov"]) {
      throw "Choose either pretty-print or lcov output";
    }
  
    env.prettyPrint = args["pretty-print"];
    env.lcov = args["lcov"];
    env.verbose = args["verbose"];
    env.workers = int.parse("${args["workers"]}");
  }
  
negative.code: 
    var args = parser.parse(new Options().arguments);
  
    printUsage() {
      print("Usage: dart full-coverage.dart [OPTION...]\n");
      print(parser.getUsage());
    }
  
    fail(String msg) {
      print("\n$msg\n");
      printUsage();
      exit(1);
    }
  
    if (args["help"]) {
      printUsage();
      exit(0);
    }
  
  