code: def finish(request, socket, context):
      
      try:
          user = context["user"]
      except KeyError:
          return
      left = {"action": "leave", "name": user.name, "id": user.id}
      socket.broadcast_channel(left)
      user.delete()
docs: Event handler for a socket session ending in a room. Broadcast
      the user leaving and delete them from the DB.