static KiePMMLDerivedField getKiePMMLDerivedField(final DerivedField derivedField,
                                                      final List<Field<?>> fields) {
        DataType dataType = derivedField.getDataType() != null ? derivedField.getDataType() : getDataType(fields,derivedField.getName());
        OP_TYPE opType = derivedField.getOpType() != null ? OP_TYPE.byName(derivedField.getOpType().value()) : null;
        return KiePMMLDerivedField.builder(derivedField.getName(),
                                           getKiePMMLExtensions(derivedField.getExtensions()),
                                           DATA_TYPE.byName(dataType.value()),
                                           opType,
                                           getKiePMMLExpression(derivedField.getExpression()))
                .withDisplayName(derivedField.getDisplayName())
                .build();
    }
@Test
    void getKiePMMLDerivedField() {
        final String fieldName = "fieldName";
        final DerivedField toConvert = getDerivedField(fieldName);
        KiePMMLDerivedField retrieved = KiePMMLDerivedFieldInstanceFactory.getKiePMMLDerivedField(toConvert,
                                                                                                  Collections.emptyList());
        commonVerifyKiePMMLDerivedField(retrieved, toConvert);
    }