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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, id, transaction=None, receipt=None):
 """ Acknowledge 'consumption' of a message by id. :param str id: identifier of the message :param str transaction: include the acknowledgement in the specified transaction """

        assert id is not None, "'id' is required"
        headers = {HDR_MESSAGE_ID: id}
        if transaction:
            headers[HDR_TRANSACTION] = transaction
        if receipt:
            headers[HDR_RECEIPT] = receipt
        self.send_frame(CMD_ACK, headers)