able to get product

internal/common/config/duration.go

@@ -0,0 +1,24 @@
+package config
+
+import "time"
+
+type Duration time.Duration
+
+func (d *Duration) UnmarshalJSON(data []byte) error {
+	if len(data) == 0 {
+		*d = 0
+		return nil
+	}
+
+	duration, err := time.ParseDuration(string(data))
+	if err != nil {
+		return err
+	}
+
+	*d = Duration(duration)
+	return nil
+}
+
+func (d Duration) Std() time.Duration {
+	return time.Duration(d)
+}