docs: private double[] knnDistances(O object) {
      KNNList knns = knnq.getKNNForObject(object, getKmax() - 1);
      double[] distances = new double[getKmax()];
      int i = 0;
      for(DoubleDBIDListIter iter = knns.iter(); iter.valid() && i < getKmax(); iter.advance(), i++) {
        distances[i] = iter.doubleValue();
      }
      return distances;
    }