class_docstr: Output channel that collects send messages in a list.
  
  (doesn't send them anywhere, just collects them).
class_docstr_tok: ["Output","channel","that","collects","send","messages","in","a","list",".","(","does","n't","send","them","anywhere",",","just","collects","them",")","."]
code: def __init__(self, message_queue: Optional[Queue] = None) -> None:
      super().__init__()
      self.messages = Queue() if not message_queue else message_queue
  
imports: import asyncio
  import copy
  import inspect
  import json
  import logging
  import structlog
  from asyncio import Queue, CancelledError
  from sanic import Blueprint, response
  from sanic.request import Request
  from sanic.response import HTTPResponse, ResponseStream
  from typing import Text, Dict, Any, Optional, Callable, Awaitable, NoReturn, Union
  import rasa.utils.endpoints
  from rasa.core.channels.channel import InputChannel, CollectingOutputChannel, UserMessage
label_desc: Use image node_id 2 to create a new QueueOutputChannel object from inherited base classes: CollectingOutputChannel with example: obj = QueueOutputChannel(message_queue)