#fixed code
                                @BeforeClass
    public static void beforeClass() {
        cluster = new LogServiceCluster(3);
        cluster.createWorkers(3);
        workers = cluster.getWorkers();
        assert(workers.size() == 3);
    }
#vulnerable code 
                                @BeforeClass
    public static void beforeClass() {
        cluster = new LogServiceCluster(3);
        cluster.createWorkers(3);
        List<LogServer> workers = cluster.getWorkers();
        assert(workers.size() == 3);
    } 
                            #location 6 
                            #vulnerability type NULL_DEREFERENCE