docs: def get(self, request, hook_id):
          """
          Verify token when configuring webhook from facebook dev.
          
          MessengerBot.id is used for verification
          """
          try:
              bot = caching.get_or_set(MessengerBot, hook_id)
          except MessengerBot.DoesNotExist:
              logger.warning("Hook id %s not associated to a bot" % hook_id)
              return Response(status=status.HTTP_404_NOT_FOUND)
          if request.query_params.get('hub.verify_token') == str(bot.id):
              return Response(int(request.query_params.get('hub.challenge')))
          return Response('Error, wrong validation token')