docs: private double naiveQueryDense(NumberVector obj, WritableDoubleDataStore scores, HashSetModifiableDBIDs cands) {
      double len = 0.; // Length of query object, for final normalization
      for(int dim = 0, max = obj.getDimensionality(); dim < max; dim++) {
        final double val = obj.doubleValue(dim);
        if(val == 0. || val != val) {
          continue;
        }
        len += val * val;
        // No matching documents in index:
        if(dim >= index.size()) {
          continue;
        }
        ModifiableDoubleDBIDList column = index.get(dim);
        for(DoubleDBIDListIter n = column.iter(); n.valid(); n.advance()) {
          scores.increment(n, n.doubleValue() * val);
          cands.add(n);
        }
      }
      return FastMath.sqrt(len);
    }