text: import User from './User.js';
  
  const App = class extends Set {
    constructor() {
      super();
    }
  
    static load(json) {
      const app = new App();
      json.forEach((f) => {
        app.addUser(User.load(f));
      });
      return app;
    }
  
    addUser(user) {
      if (!user instanceof User) return console.log('invalid User');
      super.add(user);
    }
  
    removeUser(user) {
      if (!user instanceof User) return console.log('invalid User');
      super.delete(user);
    }
  
    getUsers() {
      return [...super.values()];
    }
  
    add() {}
  
    delete() {}
  
    clear() {}
  
    values() {}
  };
  
  export default App;
  