public ModelEvaluator<?> unmarshal(InputStream is) throws SAXException, JAXBException {
Source source = ImportFilter.apply(new InputSource(is));
PMML pmml = JAXBUtil.unmarshalPMML(source);
PMMLManager pmmlManager = new PMMLManager(pmml);
return (ModelEvaluator<?>)pmmlManager.getModelManager(ModelEvaluatorFactory.getInstance());
}