presto-ml/src/main/java/io/prestosql/plugin/ml/ModelUtils.java/ModelUtils/toFeatures
class ModelUtils:    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);
    }