docs: @Override
    protected void postDelete(RdKNNEntry entry) {
      // reverse knn of o
      ModifiableDoubleDBIDList rnns = DBIDUtil.newDistanceDBIDList();
      doReverseKNN(getRoot(), ((RdKNNLeafEntry) entry).getDBID(), rnns);
  
      // knn of rnn
      ArrayModifiableDBIDs ids = DBIDUtil.newArray(rnns);
      ids.sort();
      List<? extends KNNList> knnLists = knnQuery.getKNNForBulkDBIDs(ids, settings.k_max);
  
      // adjust knn distances
      adjustKNNDistance(getRootEntry(), ids, knnLists);
    }