JpaEntityManager em = manager.createEntityManager();
em.begin();
Book book1 = new Book();
book1.setName("Oh wie schoen ist Panama");
em.persist(book1);
Book book2 = new Book();
book2.setName("Sofies Welt");
em.persist(book2);
em.commit();
System.out.println("ID: " + book1.getId() );
System.out.println("ID: " + book2.getId() );
assertNotSame(book1.getId(), book2.getId());
Book foundBook = em.find(Book.class, book1.getId());
assertSame(book1.getName(), foundBook.getName());
assertSame(book1, foundBook);
Book copyBook1 = em.copy(book1);
assertSame(book1.getName(), copyBook1.getName());
assertTrue(book1 != copyBook1);
// assertTrue(foundBook.is)