code: def on_update_stage(self, dt):
          
  
          for actor in self.actors:
              actor.on_update_game(dt)
  
          self.forum.on_update_game()
  
          with self.world._unlock_temporarily():
              self.world.on_update_game(dt)
  
          if self.world.has_game_ended():
              self.exit_stage()
docs: Sequentially update the actors, the world, and the messaging system.  
          The theater terminates once all of the actors indicate that they are done.