static KiePMMLDefineFunction getKiePMMLDefineFunction(final DefineFunction defineFunction) {
        final List<KiePMMLParameterField> kiePMMLParameterFields =
                getKiePMMLParameterFields(defineFunction.getParameterFields());
        DATA_TYPE dataType = defineFunction.getDataType() != null ?
                DATA_TYPE.byName(defineFunction.getDataType().value()) : null;
        OP_TYPE opType = defineFunction.getOpType() != null ? OP_TYPE.byName(defineFunction.getOpType().value()) : null;
        return new KiePMMLDefineFunction(defineFunction.getName(),
                                         getKiePMMLExtensions(defineFunction.getExtensions()),
                                         dataType,
                                         opType,
                                         kiePMMLParameterFields,
                                         getKiePMMLExpression(defineFunction.getExpression()));
    }
@Test
    void getKiePMMLDefineFunction() {
        final String functionName = "functionName";
        final DefineFunction toConvert = getDefineFunction(functionName);
        KiePMMLDefineFunction retrieved = KiePMMLDefineFunctionInstanceFactory.getKiePMMLDefineFunction(toConvert);
        commonVerifyKiePMMLDefineFunction(retrieved, toConvert);
    }