public Long saveBoard(final Long memberId, final BoardCreateRequest request) {
        Board board = new Board(request.title(), request.content(), memberId, request.images(), imageConverter);
        Board savedBoard = boardRepository.save(board);

        imageUploader.upload(board.getImages(), request.images());
        return savedBoard.getId();
    }
@Test
    void 게시글을_저장한다() {
        // given
        Long memberId = 1L;
        BoardCreateRequest req = new BoardCreateRequest("title", "content", new ArrayList<>());

        // when
        Long result = boardService.saveBoard(memberId, req);

        // then
        assertThat(result).isEqualTo(1L);
    }