def ack(self, tup_id):
self.failed_tuples.pop(tup_id, None)<EOL>try:<EOL><INDENT>del self.unacked_tuples[tup_id]<EOL><DEDENT>except KeyError:<EOL><INDENT>self.logger.error("<STR_LIT>", tup_id)<EOL><DEDENT>
Called when a bolt acknowledges a Tuple in the topology.

        :param tup_id: the ID of the Tuple that has been fully acknowledged in
                       the topology.
        :type tup_id: str