public void deleteAllCommentsByBoardId(final Long deletedBoardId) {
        commentRepository.deleteAllByBoardId(deletedBoardId);
    }
@Test
    void 댓글을_게시글_id로_모두_제거한다() {
        // given
        Comment saved = commentRepository.save(댓글_생성());

        // when
        assertDoesNotThrow(() -> commentService.deleteAllCommentsByBoardId(saved.getBoardId()));

        // then
        List<CommentSimpleResponse> result = commentQueryService.findAllCommentsByBoardId(saved.getBoardId(), 1L, null, 10);
        assertThat(result).isEmpty();
    }