https://blog.faceutil.com/2017/04/23/%ec%84%9c%eb%93%a0%ec%96%b4%ed%83%9d-out-of-memory-%ed%95%b4%ea%b2%b0%eb%b0%a9%eb%b2%95-%ec%84%9c%eb%93%a0-%ec%95%84%ec%9b%83%ec%98%a4%eb%b8%8c%eb%a9%94%eb%aa%a8%eb%a6%ac-%ed%95%b4%ea%b2%b0%eb%b0%a9/