#vulnerable code 
                             public Map<CQLQueryType, PreparedStatement> prepareClusteredCounterQueryMap(Session session, EntityMeta meta) {
		PropertyMeta idMeta = meta.getIdMeta();
		PropertyMeta counterMeta = meta.getFirstMeta();
		String tableName = meta.getTableName();
		String counterName = counterMeta.getPropertyName();

		RegularStatement incrStatement = prepareWhereClauseForUpdate(idMeta,
				update(tableName).with(incr(counterName, 100L)));
		String incr = incrStatement.getQueryString().replaceAll("100", "?");

		RegularStatement decrStatement = prepareWhereClauseForUpdate(idMeta,
				update(tableName).with(decr(counterName, 100L)));
		String decr = decrStatement.getQueryString().replaceAll("100", "?");

		RegularStatement selectStatement = prepareWhereClauseForSelect(idMeta, select(counterName).from(tableName));
		String select = selectStatement.getQueryString();

		RegularStatement deleteStatement = prepareWhereClauseForDelete(idMeta, QueryBuilder.delete().from(tableName));
		String delete = deleteStatement.getQueryString();

		Map<CQLQueryType, PreparedStatement> clusteredCounterPSMap = new HashMap<AchillesCounter.CQLQueryType, PreparedStatement>();
		clusteredCounterPSMap.put(INCR, session.prepare(incr.toString()));
		clusteredCounterPSMap.put(DECR, session.prepare(decr.toString()));
		clusteredCounterPSMap.put(SELECT, session.prepare(select.toString()));
		clusteredCounterPSMap.put(DELETE, session.prepare(delete.toString()));

		return clusteredCounterPSMap;
	} 
                            #location 9 
                            #vulnerability type NULL_DEREFERENCE
#fixed code
                             public Map<CQLQueryType, PreparedStatement> prepareClusteredCounterQueryMap(Session session, EntityMeta meta) {
		PropertyMeta idMeta = meta.getIdMeta();
		PropertyMeta counterMeta = meta.getFirstMeta();
		String tableName = meta.getTableName();
		String counterName = counterMeta.getPropertyName();

		RegularStatement incrementStatement = prepareWhereClauseForUpdate(idMeta,update(tableName)
                .with(incr(counterName, bindMarker())),false);

		RegularStatement decrementStatement = prepareWhereClauseForUpdate(idMeta,update(tableName)
                .with(decr(counterName, bindMarker())), false);

		RegularStatement selectStatement = prepareWhereClauseForSelect(idMeta, select(counterName).from(tableName));

		RegularStatement deleteStatement = prepareWhereClauseForDelete(idMeta, QueryBuilder.delete().from(tableName));

		Map<CQLQueryType, PreparedStatement> clusteredCounterPSMap = new HashMap<>();
		clusteredCounterPSMap.put(INCR, session.prepare(incrementStatement));
		clusteredCounterPSMap.put(DECR, session.prepare(decrementStatement));
		clusteredCounterPSMap.put(SELECT, session.prepare(selectStatement));
		clusteredCounterPSMap.put(DELETE, session.prepare(deleteStatement));

		return clusteredCounterPSMap;
	}