#fixed code
                                public Map<Long, Map<Long, CoOccurrenceItem>> createCooccurrences(Node annotatedText) {
        Map<String, Object> params = new HashMap<>();
        params.put("id", annotatedText.getId());
        String query;
        if (respectSentences) {
            query = COOCCURRENCE_QUERY_BY_SENTENCE;
        } else {
            query = COOCCURRENCE_QUERY;
        }

        Result res = null;
        try (Transaction tx = database.beginTx();) {
            res = database.execute(query, params);
            tx.success();
        } catch (Exception e) {
            LOG.error("Error while creating co-occurrences: ", e);
        }

        List<CoOccurrenceItem> prelim = new ArrayList<>();
        while (res != null && res.hasNext()) {
            Map<String, Object> next = res.next();
            Long tag1 = toLong(next.get("tag1"));
            Long tag2 = toLong(next.get("tag2"));
            String tagVal1 = (String) next.get("tag1_val");
            String tagVal2 = (String) next.get("tag2_val");
            int tag1Start = (toLong(next.get("sourceStartPosition"))).intValue();
            int tag2Start = (toLong(next.get("destinationStartPosition"))).intValue();
            List<String> pos1 = next.get("pos1") != null ? Arrays.asList((String[]) next.get("pos1")) : new ArrayList<>();
            List<String> pos2 = next.get("pos2") != null ? Arrays.asList((String[]) next.get("pos2")) : new ArrayList<>();

            // check whether POS of both tags are admitted
            boolean bPOS1 = pos1.stream().filter(pos -> admittedPOSs.contains(pos)).count() != 0  ||  pos1.size() == 0;
            boolean bPOS2 = pos2.stream().filter(pos -> admittedPOSs.contains(pos)).count() != 0  ||  pos2.size() == 0;

            // fill tag co-occurrences (adjacency matrix)
            if (bPOS1 && bPOS2) {
                prelim.add(new CoOccurrenceItem(tag1, tag1Start, tag2, tag2Start));
            }

            // for logging purposses and for `expandNamedEntities()`
            idToValue.put(tag1, tagVal1);
            idToValue.put(tag2, tagVal2);
        }

        Map<Long, List<Pair<Long, Long>>> neExp;
        if (expandNEs) {
            // process named entities: split them into individual tokens by calling ga.nlp.annotate(), assign them IDs and create co-occurrences
            neExp = expandNamedEntities();
            neExpanded = neExp.entrySet().stream()
                            .collect(Collectors.toMap( Map.Entry::getKey, e -> e.getValue().stream().map(p -> p.second()).collect(Collectors.toList()) ));
        } else
            neExp = new HashMap<>();
 
        Map<Long, Map<Long, CoOccurrenceItem>> results = new HashMap<>();
        long neVisited = 0L;
        for (CoOccurrenceItem it: prelim) {
            Long tag1 = it.getSource();
            Long tag2 = it.getDestination();
            int tag1Start = it.getSourceStartingPositions().get(0).first().intValue();
            int tag2Start = it.getSourceStartingPositions().get(0).second().intValue();

            if (expandNEs) {
                if (neExp.containsKey(tag1)) {
                    if (neVisited == 0L || neVisited != tag1.longValue()) {
                        connectTagsInNE(results, neExp.get(tag1), tag1Start);
                        neVisited = 0L;
                    }
                    tag1Start += neExp.get(tag1).get( neExp.get(tag1).size() - 1 ).first().intValue();
                    tag1 = neExp.get(tag1).get( neExp.get(tag1).size() - 1 ).second();
                }

                if (neExp.containsKey(tag2)) {
                    connectTagsInNE(results, neExp.get(tag2), tag2Start);
                    neVisited = tag2;
                    tag2 = neExp.get(tag2).get(0).second();
                } else
                    neVisited = 0L;
            }

            addTagToCoOccurrence(results, tag1, tag1Start, tag2, tag2Start);
            if (!directionsMatter) { // when direction of co-occurrence relationships is not important
                addTagToCoOccurrence(results, tag2, tag2Start, tag1, tag1Start);
            }
        }

        return results;
    }
#vulnerable code 
                                public Map<Long, Map<Long, CoOccurrenceItem>> createCooccurrences(Node annotatedText) {
        Map<String, Object> params = new HashMap<>();
        params.put("id", annotatedText.getId());
        String query;
        if (respectSentences) {
            query = COOCCURRENCE_QUERY_BY_SENTENCE;
        } else {
            query = COOCCURRENCE_QUERY;
        }

        Result res = null;
        try (Transaction tx = database.beginTx();) {
            res = database.execute(query, params);
            tx.success();
        } catch (Exception e) {
            LOG.error("Error while creating co-occurrences: ", e);
        }

        List<CoOccurrenceItem> prelim = new ArrayList<>();
        while (res != null && res.hasNext()) {
            Map<String, Object> next = res.next();
            Long tag1 = toLong(next.get("tag1"));
            Long tag2 = toLong(next.get("tag2"));
            String tagVal1 = (String) next.get("tag1_val");
            String tagVal2 = (String) next.get("tag2_val");
            int tag1Start = (toLong(next.get("sourceStartPosition"))).intValue();
            int tag2Start = (toLong(next.get("destinationStartPosition"))).intValue();
            List<String> pos1 = Arrays.asList((String[]) next.get("pos1"));
            List<String> pos2 = Arrays.asList((String[]) next.get("pos2"));

            // check whether POS of both tags are admitted
            boolean bPOS1 = pos1.stream().filter(pos -> admittedPOSs.contains(pos)).count() != 0  ||  pos1.size() == 0;
            boolean bPOS2 = pos2.stream().filter(pos -> admittedPOSs.contains(pos)).count() != 0  ||  pos2.size() == 0;

            // fill tag co-occurrences (adjacency matrix)
            if (bPOS1 && bPOS2) {
                prelim.add(new CoOccurrenceItem(tag1, tag1Start, tag2, tag2Start));
            }

            // for logging purposses and for `handleNamedEntities()`
            idToValue.put(tag1, tagVal1);
            idToValue.put(tag2, tagVal2);
        }

        Map<Long, List<Pair<Long, Long>>> neExp = expandNamedEntities();
        neExpanded = neExp.entrySet().stream()
                        .collect(Collectors.toMap( Map.Entry::getKey, e -> e.getValue().stream().map(p -> p.second()).collect(Collectors.toList()) ));
 
        Map<Long, Map<Long, CoOccurrenceItem>> results = new HashMap<>();
        long neVisited = 0L;
        for (CoOccurrenceItem it: prelim) {
            Long tag1 = it.getSource();
            Long tag2 = it.getDestination();
            int tag1Start = it.getSourceStartingPositions().get(0).first().intValue();
            int tag2Start = it.getSourceStartingPositions().get(0).second().intValue();

            if (neExp.containsKey(tag1)) {
                if (neVisited == 0L || neVisited != tag1.longValue()) {
                    connectTagsInNE(results, neExp.get(tag1), tag1Start);
                    neVisited = 0L;
                }
                tag1Start += neExp.get(tag1).get( neExp.get(tag1).size() - 1 ).first().intValue();
                tag1 = neExp.get(tag1).get( neExp.get(tag1).size() - 1 ).second();
            }

            if (neExp.containsKey(tag2)) {
                connectTagsInNE(results, neExp.get(tag2), tag2Start);
                neVisited = tag2;
                tag2 = neExp.get(tag2).get(0).second();
            } else
                neVisited = 0L;

            addTagToCoOccurrence(results, tag1, tag1Start, tag2, tag2Start);
            if (!directionsMatter) { // when direction of co-occurrence relationships is not important
                addTagToCoOccurrence(results, tag2, tag2Start, tag1, tag1Start);
            }
        }

        return results;
    } 
                            #location 62 
                            #vulnerability type NULL_DEREFERENCE