text: // Objects
  class FacebookMessenger {
    constructor() {
      this._name = 'facebook';
    }
    send(message) {
      console.log('Send to : ' + this._name);
      console.log('Send a message : ' + message);
    }
    setName(name) {
      this._name = name;
    }
  }
  
  class MessengerAdapter {
    constructor(name) {
      this._messenger = new FacebookMessenger();
      this._messenger.setName(name);
    }
    send(message) {
      this._messenger.send(message);
    }
  }
  
  class TwitterMessenger {
    constructor() {
      this._name = 'twitter';
      this._adapter = new MessengerAdapter(this._name);
    }
    send(message) {
      this._adapter.send(message);
    }
  }
  
  // Test
  const facebook = new FacebookMessenger();
  facebook.send('Hello, Keid!');
  
  const twitter = new TwitterMessenger();
  twitter.send('How are you?');
  