code: def _publish_deferred_messages(self):
          
          global message_stack
          if not self._rabbitmq_is_closed and message_stack:
              LOGGER.info('Publishing %i deferred message(s)', len(message_stack))
              while message_stack:
                  self._publish_message(*message_stack.pop())
docs: Called when pika is connected and has a channel open to publish
          any requests buffered.