docs: def request_session(token, url=None):
  	"""
  	Requests a WebSocket session for the Real-Time Messaging API.
  	
  	Returns a SessionMetadata object containing the information retrieved from
  	the API call.
  	"""
  	if url is None:
  		api = SlackApi()
  	else:
  		api = SlackApi(url)
  
  	response = api.rtm.start(token=token)
  	return SessionMetadata(response, api, token)