diff --git a/example_test.go b/example_test.go
index 61b2bf5..727edb7 100644
--- a/example_test.go
+++ b/example_test.go
@@ -22,8 +22,10 @@ func ExampleStart() {
 }
 
 func ExampleStart_startWithCancelContext() {
-  f := func(context.Context) error {
+  f := func(ctx context.Context) error {
     <-time.After(time.Second)
+    workerId := cogroup.GetWorkerId(ctx)
+    println(workerId, " did one task")
     return nil
   }