출처는 인텔리J의 Project Structure 에서 발췌 1.3 Plain old java1.4 assert keyword1.5 - 'enum' keywrod, generics, autoboxing etc..1.6 @override in interfaces1.7 diamonds, arm, multi-catch etc1.8 lamdas, type annotaions etc.1.9 modules, private methods in interfaces etc.x experimental featurs