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