https://blog.faceutil.com/2017/05/19/ios%ec%9d%98-%eb%aa%a8%eb%b0%94%ec%9d%bc-safari%eb%a1%9c-%ec%a7%81%ec%a0%91-%eb%8b%a4%ec%9a%b4%eb%b0%9b%ec%9e%90-safari-download-manager-2-0-3-%ec%97%85%eb%8d%b0%ec%9d%b4%ed%8a%b8-ios-5-%ed%98%b8/