code: def _observe_keep_screen_on(self, change):
          
          def set_screen_on(window):
              from .android_window import Window
              window = Window(__id__=window)
              if self.keep_screen_on:
                  window.addFlags(Window.FLAG_KEEP_SCREEN_ON)
              else:
                  window.clearFlags(Window.FLAG_KEEP_SCREEN_ON)
  
          self.widget.getWindow().then(set_screen_on)
docs: Sets or clears the flag to keep the screen on.