https://www.notion.so/4b0cf3f6ff7549adb2951e27519fc0e6
https://blog.baesangwoo.dev/posts/java-livestudy-8week/
https://dev-coco.tistory.com/13
https://yadon079.github.io/2021/java%20study%20halle/week-08
https://k3068.tistory.com/34
https://www.notion.so/Java-8-0cc8c251d5374ac882a4f22fa07c4e6a
https://leemoono.tistory.com/23
https://github.com/inhalin/whiteship-live-study/blob/main/week-08.md
https://velog.io/@ljs0429777/8%EC%A3%BC%EC%B0%A8-%EA%B3%BC%EC%A0%9C-%EC%9D%B8%ED%84%B0%ED%8E%98%EC%9D%B4%EC%8A%A4
https://github.com/tocgic/study-java-basic/blob/main/week8.md
https://ahnyezi.github.io/java/javastudy-8-interface/
https://github.com/integer87/study/blob/master/chapter8/chapter8.md
https://github.com/yeGenieee/java-live-study/blob/main/%5B8%5DJava%20Live%20Study.md
https://velog.io/@honux/%EB%B0%B1%EA%B8%B0%EC%84%A0-%EC%9E%90%EB%B0%94-%EB%9D%BC%EC%9D%B4%EB%B8%8C-%EC%8A%A4%ED%84%B0%EB%94%948-%EC%9D%B8%ED%84%B0%ED%8E%98%EC%9D%B4%EC%8A%A4