python opcua 订阅后断链，如何判断是否断链

使用python opcua 订阅节点之后，如果opcua断链之后，如何是她重新链接，或者如何知道是否断链

def run():
    time.sleep(3)
    logging.basicConfig(level=logging.WARN)
    base_path = os.path.dirname(os.path.dirname(__file__))
    json_file_path = os.path.join(base_path, "jsonfile")
    file_name = "hmi1.json"

    json_file = os.path.join(json_file_path, file_name)
    with open(json_file, 'r', encoding="utf-8") as f:
        json_list = json.load(f)
    client = Client(f"opc.tcp://{plc_ip}:{plc_port}")
    try:
        client.connect()
        client.load_type_definitions()
        # params = ua.CreateSubscriptionParameters()
        # params.RequestedPublishingInterval = 2000
        # params.RequestedLifetimeCount = 30000
        # params.RequestedMaxKeepAliveCount = 10000
        # params.MaxNotificationsPerPublish = 2147483649
        # params.PublishingEnabled = True
        # params.Priority = 0
        # params._freeze = True
        t1 = time.time()
        node_list = []
        area_key = ""
        for key, node_id in json_list.items():
            if key == "REEFER":
                area_key = key
                for node in node_id:
                    node_id = node.get('NodeId')
                    node_list.append(node_id)
        handler = SubHandler(json_list, area_key)
        sub = client.create_subscription(50, handler)
        for node in node_list:
            handle = sub.subscribe_data_change(client.get_node(node))
        t2 = time.time() - t1
        print(t2, "over_time")

        const = 0
        # while True:
        #     const += 1
        #     time.sleep(1)
        #     print(const)
        embed()
        print(client.disconnect())
    except Exception as e:
        print(e)
    finally:
        client.disconnect()

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