Given the code below, what will be the output of app.getService('UserService').getUserName()?

Given the code below, what will be the output of app.getService('UserService').getUserName()?

class UserService {
  constructor(logger) {
    this.logger = logger;
  }
  getUserName() {
    this.logger.log('Fetching user');
    return 'Alice';
  }
}
class Logger {
  log(msg) {
    console.log('LOG:', msg);
  }
}
const container = new Container();
container.register('Logger', Logger);
container.register('UserService', UserService, ['Logger']);
const app = container.build();