https://blog.faceutil.com/2017/05/11/%ec%9c%88%eb%8f%84%ec%9a%b0-%eb%ac%b4%ec%a0%81-%ed%8f%b4%eb%8d%94-%eb%a7%8c%eb%8a%a5-%ec%a0%9c%ec%96%b4%ed%8c%90-%ea%b0%93%eb%aa%a8%eb%93%9cgod-mode-%eb%a7%8c%eb%93%a4%ea%b8%b0-%e3%8e%b6/