def delete(self, port, qos_policy=None):
        """Remove QoS rules from port.

        :param port: port object.
        :param qos_policy: the QoS policy to be removed from port.
        """
        LOG.info("Deleting QoS policy %(qos_policy)s on port %(port)s",
                 dict(qos_policy=qos_policy, port=port))

        self._utils.remove_port_qos_rule(port["port_id"])