docs: private void linearScan(Relation<? extends O> relation, DBIDIter iter, O obj, double range, ModifiableDoubleDBIDList result) {
      final PrimitiveDistanceFunction<? super O> rawdist = this.rawdist;
      while(iter.valid()) {
        final double distance = rawdist.distance(obj, relation.get(iter));
        if(distance <= range) {
          result.add(distance, iter);
        }
        iter.advance();
      }
    }