src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts/TimerRenderer/formatDuration
class TimerRenderer:	private formatDuration(duration: number) {
		const seconds = Math.floor(duration / 1000);
		const tenths = String(duration - seconds * 1000).charAt(0);

		return `${seconds}.${tenths}s`;
	}