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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def ack(self, delivery_tag, multiple=False):
        '''
        Acknowledge delivery of a message.  If multiple=True, acknowledge up-to
        and including delivery_tag.
        '''
        args = Writer()
        args.write_longlong(delivery_tag).\
            write_bit(multiple)

        self.send_frame(MethodFrame(self.channel_id, 60, 80, args))