def consume(self, limit=None):
        """Returns an iterator that waits for one message at a time."""
        for total_message_count in count():
            if limit and total_message_count >= limit:
                raise StopIteration

            if not self.channel.is_open:
                raise StopIteration

            self.channel.wait()
            yield True
Returns an iterator that waits for one message at a time.