code: def launch_app(self, app_id, force_launch=False, callback_function=False):
          
  
          if not force_launch and self.app_id is None:
              self.update_status(lambda response:
                                 self._send_launch_message(app_id, force_launch,
                                                           callback_function))
          else:
              self._send_launch_message(app_id, force_launch, callback_function)
docs: Launches an app on the Chromecast.
  
              Will only launch if it is not currently running unless
              force_launch=True.