public void testMultiple() throws Exception {
Date date = createDate();
Map<String, Contact> contacts = new HashMap<String, Contact>();
contacts.put("id1", new Contact("Alberto", "Gimeno", Gender.MALE, date, date));
Json data = JsonSerializer.serialize(contacts);
contacts = (Map<String, Contact>) JsonSerializer.deserialize(Util.getField(User.class, "contacts"), data);
Contact contact = contacts.get("id1");
assertEquals("Alberto", contact.firstName);