anchor.diff:  import "dart:html";
  -import 'package:logging/logging.dart';
  +import "dart:mirrors";
  +import "dart:math" as math;
  +import "package:logging/logging.dart";
   
   void main() {
     Logger.root.level = Level.ALL;
  
positive.code:   }
  
    bool registerComponentObject(object) {
  
    }
  
    void keyListener(KeyboardEvent event) {
      if (event.keyCode == KeyCode.ENTER) {
        logger.fine("Start execute command: ${(event.target as InputElement).value}");
        // Execute command
        var response = new DivElement();
        var input = event.target as InputElement;
        response.innerHtml = input.value;
        input.readOnly = true;
        input.autofocus = false;
        input.parent.children.add(response);
        var session = createSession();
        input.parent.parent.children.add(session.session);
        session.input.focus();
      }
    }
  
    Session createSession() {
      var inter = new DivElement();
      var flag = new SpanElement();
      flag.innerHtml = "\$";
  
negative.code: 
    Shell shell = new Shell();
    shell.startup();
  
    shell.registerComponentObject(tools);
  }
  
  class Tools {
    void startup({String fullScreenButtonSelector: "#full_screen", String consoleSelector: "#console"}) {
      querySelector(fullScreenButtonSelector).onClick.listen((event) => querySelector(consoleSelector).requestFullscreen());
    }
  
    String help() {
      return "-- help: Print documents";
    }
  }
  
  