presto-ml/src/main/java/io/prestosql/plugin/ml/FeatureVectorUnitNormalizer.java/FeatureVectorUnitNormalizer/getSerializedData
class FeatureVectorUnitNormalizer:    @Override
    public byte[] getSerializedData()
    {
        // This transformation has no state
        return new byte[0];
    }