static Optional<Object> getValueFromPMMLResultByVariableName(final String variableName,
                                                                 final Map<String, Object> resultsVariables) {
        return Optional.ofNullable(resultsVariables.get(variableName));
    }
@Test
    void getValueFromPMMLResultByVariableName() {
        final String variableName = "variableName";
        final Map<String, Object> resultsVariables = new HashMap<>();
        Optional<Object> retrieved = KiePMMLOutputField.getValueFromPMMLResultByVariableName(variableName,
                                                                                             resultsVariables);
        assertThat(retrieved).isNotPresent();
        final Object variableValue = 243.94;
        resultsVariables.put(variableName, variableValue);
        retrieved = KiePMMLOutputField.getValueFromPMMLResultByVariableName(variableName, resultsVariables);
        assertThat(retrieved).isPresent();
        assertThat(retrieved.get()).isEqualTo(variableValue);
    }