public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            AppRibbon.UiApp = commandData.Application;
            AppRibbon.Uidoc = AppRibbon.UiApp.ActiveUIDocument;
            AppRibbon.App   = AppRibbon.UiApp.Application;
            AppRibbon.Doc   = AppRibbon.Uidoc.Document;

            OutLocation = OutputLocation.DEBUG;

            logMsgDbLn2("delete unit styles", "before");
            RevitSettingsBase.ListRevitSchema();

            RsMgr.Init();
            RsMgr.SetElementBasePoint();

            if (!RsMgr.DeleteSchema())
            {
                return(Result.Failed);
            }

            logMsg("");
            logMsgDbLn2("delete unit styles", "after");
            RevitSettingsBase.ListRevitSchema();

            logMsg("");
            return(Result.Succeeded);
        }