src/vs/workbench/contrib/notebook/browser/view/output/outputRenderer.ts/OutputRenderer/_renderMessage
class OutputRenderer:	private _renderMessage(container: HTMLElement, message: string): IRenderOutput {
		const contentNode = document.createElement('p');
		contentNode.innerText = message;
		container.appendChild(contentNode);
		return { type: RenderOutputType.Mainframe };
	}