@Test
 public void test_isAvailable_is_true_if_all_conference_rooms_have_available_seats() {
   List<ConferenceRoomAvailabilityItem> availabilityItems =
       ConferenceRoomAvailabilityItemFixture.createConferenceRoomsWithAvailableSeats(3);
   conference.setConferenceRoomAvailabilityItems(availabilityItems);
   boolean result = checker.isAvailable(conference);
   assertTrue(result);
 }
 @Test
 public void test_isAvailable_is_true_if_one_conference_room_has_available_seats() {
   List<ConferenceRoomAvailabilityItem> availabilityItems =
       ConferenceRoomAvailabilityItemFixture.createPartiallyOccupiedConferenceRooms(3);
   conference.setConferenceRoomAvailabilityItems(availabilityItems);
   boolean result = checker.isAvailable(conference);
   assertTrue(result);
 }