@Before
public void prepareDb() throws Exception {
getTransactionManager().begin();
final EntityManager em = getFactory().createEntityManager();
luke = new GrandChild();
luke.setName( "Luke" );
leia = new GrandChild();
leia.setName( "Leia" );
granny = new GrandMother();
granny.getGrandChildren().add( luke );
granny.getGrandChildren().add( leia );