presto-ml/src/main/java/io/prestosql/plugin/ml/ClassifierFeatureTransformer.java/ClassifierFeatureTransformer/ClassifierFeatureTransformer
class ClassifierFeatureTransformer:    public ClassifierFeatureTransformer(Classifier<Integer> classifier, FeatureTransformation transformation)
    {
        this.classifier = requireNonNull(classifier, "classifier is is null");
        this.transformation = requireNonNull(transformation, "transformation is null");
    }