final TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory(2);
final HazelcastInstance instance = factory.newInstances()[0];
final ISet<String> set = instance.getSet(setName);
set.add(ELEMENT);
final TransactionContext context = instance.newTransactionContext();
context.beginTransaction();
final TransactionalSet<Object> setTxn = context.getSet(setName);
setTxn.add("itemWillGetRollBacked");
context.rollbackTransaction();
assertEquals(1, set.size());