src/vs/base/browser/ui/tree/objectTreeModel.ts/ObjectTreeModel/setChildren
class ObjectTreeModel:	setChildren(
		element: T | null,
		children: Iterable<ITreeElement<T>> = Iterable.empty(),
		options: IObjectTreeModelSetChildrenOptions<T, TFilterData> = {},
	): void {
		const location = this.getElementLocation(element);
		this._setChildren(location, this.preserveCollapseState(children), options);
	}