anchor.diff:    /**
      * This constructor is to be used when running the static file handler as a standalone app.
      */
  -  StaticFileHandler(String directory, {int port: 80}) {
  +  StaticFileHandler(String documentRoot, {int port: 80, String ip: '0.0.0.0'}) {
       // If port == 0 the OS will pick a random available port for us
       if (65535 < port || 0 > port ) {
         print("Invalid port");
  
positive.code:     
      _port = port;
      
      _root = new Path(directory).canonicalize();
      
      checkDir();
    }
  
negative.code:   Future<bool> start() {
      var completer = new Completer();
      // Start the HttpServer.
      HttpServer.bind(_ip, _port)
          .then((server) {
            _server = server;
            print ("Listening on port ${_server.port}");
  