### Question:
CustomGoalServiceImpl implements CustomGoalService { @Transactional @Override public List<CustomGoalResponseDto> updateBulk(BulkCustomGoalDto bulkCustomGoalDto) { List<CustomGoalResponseDto> updatable = bulkCustomGoalDto.getCustomGoals(); List<CustomGoalResponseDto> returned = new ArrayList<>(); for (CustomGoalResponseDto el : updatable) { returned.add(update(el)); } return returned; }  @Transactional @Override List<CustomGoalResponseDto> save(BulkSaveCustomGoalDto bulkSave, User user); @Transactional @Override List<CustomGoalResponseDto> findAll(); @Transactional @Override CustomGoalResponseDto findById(Long id); @Transactional @Override List<CustomGoalResponseDto> updateBulk(BulkCustomGoalDto bulkCustomGoalDto); @Transactional @Override List<CustomGoalResponseDto> findAllByUser(Long userId); @Transactional @Override List<Long> bulkDelete(String ids);  }### Answer:
@Test public void updateEmptyInputBulkTest() { List<CustomGoalResponseDto> updateBulkResult = customGoalService.updateBulk(new BulkCustomGoalDto(Collections.emptyList())); assertTrue(updateBulkResult.isEmpty()); }