def _basic_cancel_ok(self, args):
consumer_tag = args.read_shortstr()<EOL>self._on_cancel(consumer_tag)<EOL>
Confirm a cancelled consumer

        This method confirms that the cancellation was completed.

        PARAMETERS:
            consumer_tag: shortstr

                consumer tag

                Identifier for the consumer, valid within the current
                connection.

                RULE:

                    The consumer tag is valid only within the channel
                    from which the consumer was created. I.e. a client
                    MUST NOT create a consumer in one channel and then
                    use it in another.