src/vs/platform/profiling/common/profilingModel.ts/BottomUpNode/root
class BottomUpNode:	public static root() {
		return new BottomUpNode({
			id: -1,
			selfTime: 0,
			aggregateTime: 0,
			ticks: 0,
			callFrame: {
				functionName: '(root)',
				lineNumber: -1,
				columnNumber: -1,
				scriptId: '0',
				url: '',
			},
		});
	}