Create a new consumer for a queue.

        Parameters:
          queue_name(str): The queue to consume.
          prefetch(int): The number of messages to prefetch.
          timeout(int): The idle timeout in milliseconds.

        Raises:
          QueueNotFound: If the queue hasn't been declared.

        Returns:
          Consumer: A consumer that retrieves messages from Redis.

def consume(self, queue_name, prefetch=1, timeout=100):
        """Create a new consumer for a queue.

        Parameters:
          queue_name(str): The queue to consume.
          prefetch(int): The number of messages to prefetch.
          timeout(int): The idle timeout in milliseconds.

        Raises:
          QueueNotFound: If the queue hasn't been declared.

        Returns:
          Consumer: A consumer that retrieves messages from Redis.
        """
        try:
            return _StubConsumer(
                self.queues[queue_name],
                self.dead_letters_by_queue[queue_name],
                timeout,
            )
        except KeyError:
            raise QueueNotFound(queue_name)