public static void RemoveStyleSheetFromAsset(
            BuilderDocument document, int ussIndex)
        {
            Undo.RegisterCompleteObjectUndo(
                document.visualTreeAsset, "Remove StyleSheet from UXML");

            document.RemoveStyleSheetFromDocument(ussIndex);
        }
        public static void RemoveStyleSheetsFromAsset(
            BuilderDocument document, int[] indexes)
        {
            Undo.RegisterCompleteObjectUndo(
                document.visualTreeAsset, "Remove StyleSheets from UXML");

            foreach (var index in indexes)
            {
                document.RemoveStyleSheetFromDocument(index);
            }
        }