How to use the gmqtt.mqtt.property.Property.factory function in gmqtt

def _parse_properties(self, packet):
        if self.protocol_version < MQTTv50:
            # If protocol is version is less than 5.0, there is no properties in packet
            return {}, packet
        properties_len, left_packet = unpack_variable_byte_integer(packet)
        packet = left_packet[:properties_len]
        left_packet = left_packet[properties_len:]
        properties_dict = defaultdict(list)
        while packet:
            property_identifier, = struct.unpack("!B", packet[:1])
            property_obj = Property.factory(id_=property_identifier)
            if property_obj is None:
                logger.critical('[PROPERTIES] received invalid property id {}, disconnecting'.format(property_identifier))
                return None, None
            result, packet = property_obj.loads(packet[1:])
            for k, v in result.items():
                properties_dict[k].append(v)
        properties_dict = dict(properties_dict)
        return properties_dict, left_packet

def _build_properties_data(cls, properties_dict, protocol_version):
        if protocol_version < MQTTv50:
            return bytearray()
        data = bytearray()
        for property_name, property_value in properties_dict.items():
            property = Property.factory(name=property_name)
            if property is None:
                logger.warning('[GMQTT] property {} is not supported, it was ignored'.format(property_name))
                continue
            property_bytes = property.dumps(property_value)
            data.extend(property_bytes)
        result = pack_variable_byte_integer(len(data))
        result.extend(data)
        return result