# File lib/bunny/queue09.rb, line 67
                def ack(opts={})
                        # Set delivery tag
                        if delivery_tag.nil? and opts[:delivery_tag].nil?
                                raise Bunny::AcknowledgementError, "No delivery tag received"
                        else
                                self.delivery_tag = opts[:delivery_tag] if delivery_tag.nil?
                        end
                        
      client.send_frame(
        Qrack::Protocol09::Basic::Ack.new({:delivery_tag => delivery_tag, :multiple => false}.merge(opts))
      )

                        # reset delivery tag
                        self.delivery_tag = nil
    end