def _make_qos_filter_dict(self, qos_filter, fields=None):
        res = {'id': qos_filter.id,
               'tenant_id': qos_filter.tenant_id,
               'qos_id': qos_filter.qos_id,
               'queue_id': qos_filter.queue_id,
               'prio': qos_filter.prio,
               'protocol': qos_filter.protocol,
               'src_port': qos_filter.src_port,
               'dst_port': qos_filter.dst_port,
               'src_addr': qos_filter.src_addr,
               'dst_addr': qos_filter.dst_addr}

        if qos_filter.custom_match is not None:
            res.update({'custom_match': qos_filter.custom_match})

        return self._fields(res, fields)