em.getTransaction().begin();
em.persist(mi);
em.getTransaction().commit();
em.clear();
MenuItem mi2 = em.find(MenuItem.class, mi.getId());
assertEquals(mi2.getId(), mi.getId());
Map<String, Ingredient> ing2 = mi2.getIngredients();
assertTrue(ing2.containsKey("Peanut Butter"));
Quantity q = ing2.get("Peanut Butter").getQuantity();