@Transactional
    public Long saveTradeHistory(final TradeHistoryCreateRequest request) {
        TradeHistory tradeHistory = new TradeHistory(
                request.buyerId(),
                request.sellerId(),
                request.productId(),
                request.productOriginPrice(),
                request.productDiscountPrice(),
                request.usingCouponIds()
        );

        TradeHistory savedTradeHistory = tradeHistoryRepository.save(tradeHistory);
        return savedTradeHistory.getId();
    }
@Test
    void 거래_내역을_저장한다() {
        // given
        TradeHistoryCreateRequest request = new TradeHistoryCreateRequest(
                1L,
                2L,
                1L,
                10000,
                10,
                List.of()
        );

        // when
        Long result = memberService.saveTradeHistory(request);

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