anchor.diff:   * Middleware to modify incoming request and hands it to the innerHandler.
    * Returns new Future<shelf.Response> object.
    */
  -shelf.Middleware myMiddleware() {
  -  return (shelf.Handler innerHandler) {
  -    return (shelf.Request request) {
  -      return new Future.sync(() => innerHandler(request))
  -          .then((shelf.Response response) {
  -        return modifyResponse(response);
  -      });
  -    };
  -  };
  -}
  +shelf.Middleware myMiddleware =
  +    shelf.createMiddleware(responseHandler: modifyResponse);
   
   /**
    * Small function that modifies an outgoing response.
  
positive.code: void main() async {
    var server = await io.serve(myHandler, '127.0.0.1', 8080);
    print('Serving at http://${server.address.host}:${server.port}');
  }
negative.code:  * Compose a set of Middleware and a Handler.
   */
  var myHandler = const shelf.Pipeline()
      .addMiddleware(myMiddleware)
      .addHandler(simpleHandler);
  
  /**
  