add ExposeLag option, to be able to disable lag exporting

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

options.go

@@ -14,7 +14,7 @@ var (
 	DefaultCommitInterval = 5 * time.Second
 
 	// DefaultStatsInterval specifies how fast check consumer lag
-	DefaultStatsInterval = 5 * time.Second
+	DefaultStatsInterval = 30 * time.Second
 
 	// DefaultSubscribeMaxInflight specifies how much messages keep inflight
 	DefaultSubscribeMaxInflight = 100
@@ -116,3 +116,10 @@ type subscribeMessagePoolKey struct{}
 func SubscribeMessagePool(b bool) broker.SubscribeOption {
 	return broker.SetSubscribeOption(subscribeMessagePoolKey{}, b)
 }
+
+type exposeLagKey struct{}
+
+// ExposeLag enabled subscriber lag via [meter.Meter]
+func ExposeLag(b bool) broker.Option {
+	return broker.SetOption(exposeLagKey{}, b)
+}