#vulnerable code 
                                private List<StepData> buildBranchesData(List<LanguageEventData> data) {
        List<StepData> branches = Lists.newArrayList();

        for (LanguageEventData branchData : data) {
            String path = branchData.getPath();
            String stepName = branchData.getStepName();
            ReturnValues returnValues = (ReturnValues) branchData.get(RuntimeConstants.BRANCH_RETURN_VALUES_KEY);
            branches.add(
                    new StepData(
                            path,
                            stepName,
                            new HashMap<String, Value>(),
                            returnValues.getOutputs(),
                            null, returnValues.getResult()
                    )
            );
        }

        return branches;
    } 
                            #location 13 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                                private List<StepData> buildBranchesData(List<LanguageEventData> data) {
        List<StepData> branches = Lists.newArrayList();

        for (LanguageEventData branchData : data) {
            String path = branchData.getPath();
            String stepName = branchData.getStepName();
            branches.add(
                    new StepData(
                            path,
                            stepName,
                            new HashMap<String, Value>(),
                            new HashMap<String, Value>(),
                            null, (String)branchData.get(LanguageEventData.RESULT)
                    )
            );
        }

        return branches;
    }