presto-ml/src/main/java/io/prestosql/plugin/ml/MLFunctions.java/MLFunctions/classify
class MLFunctions:    @ScalarFunction
    @SqlType(StandardTypes.BIGINT)
    public static long classify(@SqlType(MAP_BIGINT_DOUBLE) Block featuresMap, @SqlType("Classifier(bigint)") Slice modelSlice)
    {
        FeatureVector features = ModelUtils.toFeatures(featuresMap);
        Model model = getOrLoadModel(modelSlice);
        checkArgument(model.getType().equals(BIGINT_CLASSIFIER), "model is not a Classifier(bigint)");
        Classifier<Integer> classifier = (Classifier<Integer>) model;
        return classifier.classify(features);
    }