code: public static FeatureVector toFeatures(Block map)
      {
          Map<Integer, Double> features = new HashMap<>();
  
          if (map != null) {
              for (int position = 0; position < map.getPositionCount(); position += 2) {
                  features.put((int) BIGINT.getLong(map, position), DOUBLE.getDouble(map, position + 1));
              }
          }
          return new FeatureVector(features);
      }
docs: TODO: instead of having this function, we should add feature extractors that extend Model and extract features from Strings