src/vs/base/browser/ui/tree/compressedObjectTreeModel.ts/CompressedObjectTreeModel/getLastElementAncestor
class CompressedObjectTreeModel:	getLastElementAncestor(location?: T | null | undefined): ICompressedTreeNode<T> | null | undefined {
		const compressedNode = typeof location === 'undefined' ? undefined : this.getCompressedNode(location);
		return this.model.getLastElementAncestor(compressedNode);
	}