src/vs/base/browser/ui/tree/indexTreeModel.ts/IndexTreeModel/getTreeNode
class IndexTreeModel:	private getTreeNode(location: number[], node: IIndexTreeNode<T, TFilterData> = this.root): IIndexTreeNode<T, TFilterData> {
		if (!location || location.length === 0) {
			return node;
		}

		const [index, ...rest] = location;

		if (index < 0 || index > node.children.length) {
			throw new TreeError(this.user, 'Invalid tree location');
		}

		return this.getTreeNode(rest, node.children[index]);
	}