docs: private void step2(DBIDRef id, DBIDArrayIter it, int n, DistanceQuery<? super O> distQuery, WritableDoubleDataStore m) {
      for(it.seek(0); it.getOffset() < n; it.advance()) {
        // M(i) = dist(i, n+1)
        m.putDouble(it, distQuery.distance(it, id));
      }
    }