def basic_ack(self, delivery_tag, multiple=False):
        """Acknowledge one or more messages

        This method acknowledges one or more messages delivered via
        the Deliver or Get-Ok methods.  The client can ask to confirm
        a single message or a set of messages up to and including a
        specific message.

        PARAMETERS:
            delivery_tag: longlong

                server-assigned delivery tag

                The server-assigned and channel-specific delivery tag

                RULE:

                    The delivery tag is valid only within the channel
                    from which the message was received.  I.e. a client
                    MUST NOT receive a message on one channel and then
                    acknowledge it on another.

                RULE:

                    The server MUST NOT use a zero value for delivery
                    tags.  Zero is reserved for client use, meaning "all
                    messages so far received".

            multiple: boolean

                acknowledge multiple messages

                If set to True, the delivery tag is treated as "up to
                and including", so that the client can acknowledge
                multiple messages with a single method.  If set to
                False, the delivery tag refers to a single message.
                If the multiple field is True, and the delivery tag
                is zero, tells the server to acknowledge all
                outstanding mesages.

                RULE:

                    The server MUST validate that a non-zero delivery-
                    tag refers to an delivered message, and raise a
                    channel exception if this is not the case.

        """
        args = AMQPWriter()
        args.write_longlong(delivery_tag)
        args.write_bit(multiple)
        self._send_method((60, 80), args)
Acknowledge one or more messages

        This method acknowledges one or more messages delivered via
        the Deliver or Get-Ok methods.  The client can ask to confirm
        a single message or a set of messages up to and including a
        specific message.

        PARAMETERS:
            delivery_tag: longlong

                server-assigned delivery tag

                The server-assigned and channel-specific delivery tag

                RULE:

                    The delivery tag is valid only within the channel
                    from which the message was received.  I.e. a client
                    MUST NOT receive a message on one channel and then
                    acknowledge it on another.

                RULE:

                    The server MUST NOT use a zero value for delivery
                    tags.  Zero is reserved for client use, meaning "all
                    messages so far received".

            multiple: boolean

                acknowledge multiple messages

                If set to True, the delivery tag is treated as "up to
                and including", so that the client can acknowledge
                multiple messages with a single method.  If set to
                False, the delivery tag refers to a single message.
                If the multiple field is True, and the delivery tag
                is zero, tells the server to acknowledge all
                outstanding mesages.

                RULE:

                    The server MUST validate that a non-zero delivery-
                    tag refers to an delivered message, and raise a
                    channel exception if this is not the case.