src/vs/base/browser/ui/tree/indexTree.ts/IndexTree/constructor
class IndexTree:	constructor(
		user: string,
		container: HTMLElement,
		delegate: IListVirtualDelegate<T>,
		renderers: ITreeRenderer<T, TFilterData, any>[],
		private rootElement: T,
		options: IIndexTreeOptions<T, TFilterData> = {}
	) {
		super(user, container, delegate, renderers, options);
	}