src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts/MarkupCellRenderer/disposeElement
class MarkupCellRenderer:	disposeElement(element: ICellViewModel, _index: number, templateData: MarkdownCellRenderTemplate): void {
		templateData.elementDisposables.clear();
		element.getCellDecorations().forEach(e => {
			if (e.className) {
				templateData.container.classList.remove(e.className);
			}
		});
	}