case EventUpdateVolume:
        if v.OldVolume != nil {
            return &WatchMessage_Event{Action: WatchActionKindUpdate, Object: &Object{Object: &Object_Volume{Volume: v.Volume}}, OldObject: &Object{Object: &Object_Volume{Volume: v.OldVolume}}}
        } else {
            return &WatchMessage_Event{Action: WatchActionKindUpdate, Object: &Object{Object: &Object_Volume{Volume: v.Volume}}}