when i use etcdv3 to connect to a fake endpoint,no error return and program is blocking

[pysyw]

my code：
(127.0.0.1:23799: fake connection)

etcdv3.NewClient(context.Background(), []string{"127.0.0.1:23799"}, options)

err = client.Register( etcdv3.Service{
		Key: "/key",
		Value: "127.0.0.1:8080",
		TTL: etcdv3.NewTTLOption(time.Second*3, time.Second*3),
	})

There is no error return, and the program is blocking