public class MyTest extends EntityTestCase {

  @Test
  public void testPersistAndRead() {

    // an entity manager is provided by jee5unit with this method
    EntityManager em = getEntityManager();
    em.getTransaction().begin()

    MyEntity entity = new MyEntity();
    entity.setSomeValue("toSomevalue");

    MyCascadedEntity related = new MyCascadedEntity();
    entity.setRelated(related);

    em.persist(entity);

    // this will make hibernate flush the operation down to the
    // database transaction and will make mapping errors, nullable=false etc
    // fields cause errors just as if we would commit the transaction
    em.flush();

    // if we don't clear the context before reading the entity again
    // we will just get a reference to "entity" from above since it already
    // is loaded and we will not cover any possible read related errors
    // with our entity mappings
    em.clear();

    List<MyEntity> result = em.createQuery("SELECT m FROM MyEntity m").getResultList();
    assertEquals(1, result.size());

    // check that the cascade persist did happen
    assertNotNull(result.get(0).getRelated());

    // this is important since the jee5unit framework does not clear the database
    // in any way between the test methods or test cases
    em.getTransaction().rollback();
  }

  ...

@RunWith(TxRollbackRunner.class)
public class MyTest extends EntityTestCase {

   @Test
   public void testMethod() {

   ...