diff --git a/cluster/router/tag/tag_router_test.go b/cluster/router/tag/tag_router_test.go
index 17ebcdeaee48432f8c388a12d14a03c957dfc33f..280b56c8ccb69eb5d32dae2369bdc862adb8e6fd 100644
--- a/cluster/router/tag/tag_router_test.go
+++ b/cluster/router/tag/tag_router_test.go
@@ -32,6 +32,7 @@ import (
 	"github.com/apache/dubbo-go/protocol/invocation"
 )
 
+// MockInvoker is only mock the Invoker to support test tagRouter
 type MockInvoker struct {
 	url          common.URL
 	available    bool