docs: protected void objectsRemoved(DBIDs ids) {
      final Logging log = getLogger();
      StepProgress stepprog = log.isVerbose() ? new StepProgress(3) : null;
  
      // delete the materialized (old) kNNs
      log.beginStep(stepprog, 1, "New deletions ocurred, remove their materialized kNNs.");
      for(DBIDIter iter = ids.iter(); iter.valid(); iter.advance()) {
        storage.delete(iter);
      }
  
      // update the affected kNNs
      log.beginStep(stepprog, 2, "New deletions ocurred, update the affected kNNs.");
      ArrayDBIDs rkNN_ids = updateKNNsAfterDeletion(ids);
  
      // inform listener
      log.beginStep(stepprog, 3, "New deletions ocurred, inform listeners.");
      fireKNNsRemoved(ids, rkNN_ids);
  
      log.ensureCompleted(stepprog);
    }