src/vs/workbench/contrib/markers/browser/markersView.ts/createResourceMarkersIterator
function createResourceMarkersIterator(resourceMarkers: ResourceMarkers): Iterable<ITreeElement<MarkerElement>> {
	return Iterable.map(resourceMarkers.markers, m => {
		const relatedInformationIt = Iterable.from(m.relatedInformation);
		const children = Iterable.map(relatedInformationIt, r => ({ element: r }));

		return { element: m, children };
	});
}