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