chore: refactor code (#5352)

core/discov/subscriber.go

@@ -105,6 +105,7 @@ type (
 		AddListener(listener func())
 		GetValues() []string
 	}
+
 	container struct {
 		exclusive bool
 		values    map[string][]string

core/discov/subscriber_test.go

@@ -205,6 +205,7 @@ func TestSubscriber(t *testing.T) {
 	sub := new(Subscriber)
 	Exclusive()(sub)
 	c := newContainer(sub.exclusive)
+	WithContainer(c)(sub)
 	sub.items = c
 	var count int32
 	sub.AddListener(func() {