diff --git a/util/timer/example_test.go b/util/timer/example_test.go
deleted file mode 100644
index f8a1d13..0000000
--- a/util/timer/example_test.go
+++ /dev/null
@@ -1,67 +0,0 @@
-package timer_test
-
-import (
-	"fmt"
-	"github.com/name5566/leaf/timer"
-	"time"
-)
-
-func ExampleTimer() {
-	d := timer.NewDispatcher(10)
-
-	// timer 1
-	d.AfterFunc(1, func() {
-		fmt.Println("My name is Leaf")
-	})
-
-	// timer 2
-	t := d.AfterFunc(1, func() {
-		fmt.Println("will not print")
-	})
-	t.Stop()
-
-	// dispatch
-	(<-d.ChanTimer).Cb()
-
-	// Output:
-	// My name is Leaf
-}
-
-func ExampleCronExpr() {
-	cronExpr, err := timer.NewCronExpr("0 * * * *")
-	if err != nil {
-		return
-	}
-
-	fmt.Println(cronExpr.Next(time.Date(
-		2000, 1, 1,
-		20, 10, 5,
-		0, time.UTC,
-	)))
-
-	// Output:
-	// 2000-01-01 21:00:00 +0000 UTC
-}
-
-func ExampleCron() {
-	d := timer.NewDispatcher(10)
-
-	// cron expr
-	cronExpr, err := timer.NewCronExpr("* * * * * *")
-	if err != nil {
-		return
-	}
-
-	// cron
-	var c *timer.Cron
-	c = d.CronFunc(cronExpr, func() {
-		fmt.Println("My name is Leaf")
-		c.Stop()
-	})
-
-	// dispatch
-	(<-d.ChanTimer).Cb()
-
-	// Output:
-	// My name is Leaf
-}