code: def __update_keyboard(self, milliseconds):
          
          if Ragnarok.get_world().Keyboard.is_clicked(self.move_up_button):
              self.move_up()
          elif Ragnarok.get_world().Keyboard.is_clicked(self.move_down_button):
              self.move_down()
          elif Ragnarok.get_world().Keyboard.is_clicked(self.select_button):
              self.gui_buttons[self.current_index].clicked_action()
  
          for button in self.gui_buttons:
              button.update(milliseconds)
docs: Use the keyboard to control selection of the buttons.