void AddStyleSheetsToRootAsset(VisualElementAsset rootAsset, string newUssPath = null, int newUssIndex = 0)
        {
            if (rootAsset.fullTypeName == BuilderConstants.SelectedVisualTreeAssetSpecialElementTypeName)
            {
                return;
            }

            rootAsset.ClearStyleSheets();

            for (int i = 0; i < m_OpenUSSFiles.Count; ++i)
            {
                var localUssPath = m_OpenUSSFiles[i].assetPath;

                if (!string.IsNullOrEmpty(newUssPath) && i == newUssIndex)
                {
                    localUssPath = newUssPath;
                }

                if (string.IsNullOrEmpty(localUssPath))
                {
                    continue;
                }

                rootAsset.AddStyleSheet(m_OpenUSSFiles[i].styleSheet);
                rootAsset.AddStyleSheetPath(localUssPath);
            }
        }