class_docstr: Manages interactions between agents on a websocket as well as direct interactions
  between agents and an overworld.
class_docstr_tok: ["Manages","interactions","between","agents","on","a","websocket","as","well","as","direct","interactions","between","agents","and","an","overworld","."]
docstr: Defined to shutown the tornado application.
docstr_tok: ["Defined","to","shutown","the","tornado","application","."]
code: def shutdown(self):
      """
      Defined to shutown the tornado application.
      """
      try:
          self.world_runner.shutdown()
          self._expire_all_conversations()
      finally:
          pass
      tornado.ioloop.IOLoop.current().stop()
  
imports: import json
  import asyncio
  import logging
  from parlai.core.agents import create_agent
  from parlai.chat_service.core.chat_service_manager import ChatServiceManager
  import parlai.chat_service.utils.logging
  import parlai.chat_service.utils.misc
  from parlai.chat_service.services.websocket.sockets import MessageSocketHandler
  from .agents import WebsocketAgent
  import tornado
  from tornado.options import options
label_desc: Use image node_id 8 for calling the WebsocketManager obj's underlying member method code with example usage: obj.shutdown() without return types