#vulnerable code 
                                @Test
    public void testValues() throws Exception {
        // compile
        URI resource = getClass().getResource("/yaml/sensitive/sensitive_values_op.sl").toURI();
        CompilationArtifact compilationArtifact = slang.compile(SlangSource.fromFile(resource), new HashSet<SlangSource>());

        // trigger
        Map<String, StepData> steps = prepareAndRun(compilationArtifact);

        // verify
        StepData flowData = steps.get(EXEC_START_PATH);
        StepData stepData = steps.get(FIRST_STEP_PATH);

        verifyInOutParams(flowData.getInputs());
        verifyInOutParams(flowData.getOutputs());
        verifyInOutParams(stepData.getInputs());
        verifyInOutParams(stepData.getOutputs());
        verifySuccessResult(flowData);
    } 
                            #location 16 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                @Test
    public void testValues() throws Exception {
        // compile
        URI resource = getClass().getResource("/yaml/sensitive/sensitive_values_op.sl").toURI();
        CompilationArtifact compilationArtifact = slang.compile(SlangSource.fromFile(resource), new HashSet<SlangSource>());

        // trigger
        Map<String, StepData> steps = prepareAndRun(compilationArtifact);

        // verify
        StepData flowData = steps.get(EXEC_START_PATH);

        verifyInOutParams(flowData.getInputs());
        verifyInOutParams(flowData.getOutputs());
    }