public static HazelcastInstance getOrCreateHazelcastInstance() {
        return HazelcastInstanceFactory.getOrCreateHazelcastInstance(null);
    }
@Test(expected = IllegalArgumentException.class)
    public void getOrCreateHazelcastInstance_nullName() {
        Config config = new Config();
        Hazelcast.getOrCreateHazelcastInstance(config);
    }