presto-ml/src/main/java/io/prestosql/plugin/ml/LearnLibSvmVarcharClassifierAggregation.java/LearnLibSvmVarcharClassifierAggregation/output
class LearnLibSvmVarcharClassifierAggregation:    @OutputFunction("Classifier(varchar)")
    public static void output(@AggregationState LearnState state, BlockBuilder out)
    {
        Dataset dataset = new Dataset(state.getLabels(), state.getFeatureVectors(), state.getLabelEnumeration().inverse());
        Model model = new StringClassifierAdapter(new ClassifierFeatureTransformer(new SvmClassifier(LibSvmUtils.parseParameters(state.getParameters().toStringUtf8())), new FeatureUnitNormalizer()));
        model.train(dataset);
        VARCHAR_CLASSIFIER.writeSlice(out, ModelUtils.serialize(model));
    }