src/vs/base/browser/ui/tree/indexTreeModel.ts/IndexTreeModel/updateNodeAfterFilterChange
class IndexTreeModel:	private updateNodeAfterFilterChange(node: IIndexTreeNode<T, TFilterData>): ITreeNode<T, TFilterData>[] {
		const previousRenderNodeCount = node.renderNodeCount;
		const result: ITreeNode<T, TFilterData>[] = [];

		this._updateNodeAfterFilterChange(node, node.visible ? TreeVisibility.Visible : TreeVisibility.Hidden, result);
		this._updateAncestorsRenderNodeCount(node.parent, result.length - previousRenderNodeCount);

		return result;
	}