use fmt.Appendf

map_test.go

@@ -106,7 +106,7 @@ func TestOpen(t *testing.T) {
 func TestMainMethods(t *testing.T) {
 	key := "key"
 	value := "value"
-	b := []byte(fmt.Sprintf("%s = %s", key, value))
+	b := fmt.Appendf([]byte{}, "%s = %s", key, value)
 	r := bytes.NewReader(b)
 
 	m := make(Map)