anchor.diff:      
       _port = port;
       
  -    _root = new Path(directory).canonicalize();
  +    _root = new Path(documentRoot).canonicalize();
  +    
  +    // @todo: check that the IP is valid
  +    _ip = ip;
       
       checkDir();
     }
  
positive.code:   Future<bool> start() {
      var completer = new Completer();
      // Start the HttpServer.
      HttpServer.bind("0.0.0.0", this._port)
          .then((server) {
            _server = server;
            print ("Listening on port ${_server.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",
  