###Object.preventExtensions
- Make object non-extensible (can't add properties)
###Object.seal
- Make object non-extensible (can't add properties)
- Make object's own properties non-configurable (can't remove them, or change their nature and/or attributes)
###Object.freeze
- Make object non-extensible (can't add properties)
- Make object's own properties non-configurable (can't remove them, or change their nature and/or attributes)