public string Histories(Context context, int id)
        {
            var log  = new SysLogModel(context: context);
            var json = RegistrationUtilities.Histories(
                context: context,
                ss: SiteSettingsUtilities.RegistrationsSiteSettings(context: context),
                registrationId: id);

            log.Finish(context: context, responseSize: json.Length);
            return(json);
        }