docs: def register_button_handler(self, button_handler, button_sname: str):
          """
          Register a handler function which will be called when a button is pressed
  
          :param button_handler:
              A function which will be called when any of the specified buttons are pressed. The
              function is called with the Button that was pressed as the sole argument.
          :param button_sname:
              The sname of the button which should trigger the handler function
          :return:
              A no-arg function which can be used to remove this registration
          """
          return self.buttons.register_button_handler(button_handler, self.buttons[button_sname])