Add Script example.

v2/example_test.go

@@ -145,6 +145,34 @@ func ExamplePubSub() {
 	// &{mychannel hello} <nil>
 }
 
+func ExampleScript() {
+	client := redis.NewTCPClient(&redis.Options{
+		Addr: ":6379",
+	})
+	defer client.Close()
+
+	setnx := redis.NewScript(`
+		if redis.call("get", KEYS[1]) == false then
+			redis.call("set", KEYS[1], ARGV[1])
+			return 1
+		end
+		return 0
+	`)
+
+	run1 := setnx.Run(client, []string{"keynx"}, []string{"foo"})
+	fmt.Println(run1.Val().(int64), run1.Err())
+
+	run2 := setnx.Run(client, []string{"keynx"}, []string{"bar"})
+	fmt.Println(run2.Val().(int64), run2.Err())
+
+	get := client.Get("keynx")
+	fmt.Println(get)
+
+	// Output: 1 <nil>
+	// 0 <nil>
+	// GET keynx: foo
+}
+
 func Example_customCommand() {
 	Get := func(client *redis.Client, key string) *redis.StringCmd {
 		cmd := redis.NewStringCmd("GET", key)