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Negative acknowledge of one or more messages. If `multiple` is set to `true`, all messages up to the
one specified by `delivery_tag` are considered as not acknowledged by the server. If `requeue` is set
to `true`, the message will be returned to the queue and redelivered to the next available consumer.

This is a RabbitMQ specific extension to AMQP 0.9.1. It is equivalent to reject, but allows rejecting
multiple messages using the `multiple` option.
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