참고

• Object.defineProperty() - JavaScript | MDN (mozilla.org)
• https://blog.woolta.com/categories/3/posts/143
• Object.freeze vs Object.seal - 불변성과 관련된 두 가지 네이티브 메서드 | TOAST UI :: Make Your Web Delicious!

Object.defineProperty()

Object.seal(obj)

Object.freeze(obj)