https://blog.faceutil.com/2017/05/07/%ed%8c%8c%ed%8b%b0%ec%85%98-%ed%85%8c%ec%9d%b4%eb%b8%94-split-%ec%9e%91%ec%97%85-%ec%8a%a4%ed%81%ac%eb%a6%bd%ed%8a%b8-%e3%8e%b8/