https://github.com/parkgaram/java-designpattern GitHub ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑ https://www.youtube.com/watch?v=UEjsbd3IZvA&list=PLsoscMhnRc7pPsRHmgN4M8tqUdWZzkpxY Youtube 동영상 ↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
