https://blog.faceutil.com/2017/04/12/sdelete-%ec%98%a4%eb%a5%b8%ec%aa%bd-%eb%b2%84%ed%8a%bc-%eb%a9%94%eb%89%b4%ec%97%90-%ec%b6%94%ea%b0%80%ed%95%98%ec%97%ac-%eb%b3%b4%ec%95%88-%ec%82%ad%ec%a0%9c%eb%a5%bc-%eb%b3%b4%eb%8b%a4-%ec%89%bd/