Config config = new Config();
final String name = "defMM";
config.getMultiMapConfig(name).setValueCollectionType(MultiMapConfig.ValueCollectionType.SET);
final int insCount = 4;
TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory(insCount);
final HazelcastInstance[] instances = factory.newInstances(config);
assertTrue(getMultiMap(instances, name).put("key1", "key1_value1"));
assertTrue(getMultiMap(instances, name).put("key1", "key1_value2"));
assertTrue(getMultiMap(instances, name).put("key2", "key2_value1"));