@Test
 public void ModelsClass() {
   assertFalse("Class is not registred", Registration.isRegistered(Author.class));
   Registration.get(Author.class);
   assertTrue("Class is registred", Registration.isRegistered(Author.class));
 }
 @Test
 public void RegisterModels() {
   assertFalse("Class is not registred", Registration.isRegistered(Book.class));
   Registration.register(Book.class);
   assertTrue("Class is registred", Registration.isRegistered(Book.class));
 }