presto-ml/src/main/java/io/prestosql/plugin/ml/EvaluateClassifierPredictionsStateFactory.java/EvaluateClassifierPredictionsStateFactory/createGroupedState
class EvaluateClassifierPredictionsStateFactory:    @Override
    public EvaluateClassifierPredictionsState createGroupedState()
    {
        return new GroupedEvaluateClassifierPredictionsState();
    }