protected override IEnumerable <IBuilder> GetBuilders() => new IBuilder[]
 {
     TypesInfo.CreateModelBuilder <DemoTaskModelBuilder>()
 };
 protected override IEnumerable <IBuilder> GetBuilders() => new IBuilder[]
 {
     TypesInfo.CreateModelBuilder <MailSettingsModelBuilder>(),
     TypesInfo.CreateModelBuilder <MailAccountModelBuilder>(),
     TypesInfo.CreateModelBuilder <MailModelBuilder>(),
 };