class_docstr: Example one person world that lets two users chat.
class_docstr_tok: ["Example","one","person","world","that","lets","two","users","chat","."]
code: def generate_world(opt, agents):
      return MessengerChatTaskWorld(opt, agents)
  
imports: from parlai.core.worlds import World
  from parlai.chat_service.services.messenger.worlds import OnboardWorld
label_desc: Use image node_id 2 for calling the MessengerChatTaskWorld obj's underlying member method code with example usage: obj.generate_world(opt, agents) and returns: MessengerChatTaskWorld