class Logger {
  log(msg) {
    return `[LOG]: ${msg}`;
  }
}

class Formatter {
  format(text) {
    return text.toUpperCase();
  }
}

class Service {
  constructor(logger, formatter) {
    this.logger = logger;
    this.formatter = formatter;
  }
  
  process(data) {
    const formatted = this.formatter.format(data);
    return this.logger.log(formatted);
  }
}

const service = new Service(new Logger(), new Formatter());
console.log(service.process('hello world'));