@property<EOL><INDENT>def scale(self):<DEDENT>
if self.__scale:<EOL><INDENT>return self.__scale<EOL><DEDENT>v = max(self.screenshot().size) / max(self.window_size())<EOL>self.__scale = round(v)<EOL>return self.__scale<EOL>
UIKit scale factor

Refs:
    https://developer.apple.com/library/archive/documentation/DeviceInformation/Reference/iOSDeviceCompatibility/Displays/Displays.html