### Question:
DailySummaryServiceImpl implements DailySummaryService { @Override public CommonResult getFirstSummaryDate(Integer cashierId){ String firstSummaryDate = dailySummaryLogMapper.getFirstSummaryDate(cashierId); if (firstSummaryDate == null) return CommonResult.success(null); else return CommonResult.success(firstSummaryDate); }  @Override CommonResult getLastEndDate(Integer cashierId); @Override CommonResult listLogsByCashierIdAndDate(DailySummaryParam dailySummaryParam); @Override CommonResult freezeTransactionLogs(DailySummaryParam dailySummaryParam); @Override CommonResult listHistorySummaryLogs(DailySummaryParam dailySummaryParam); @Override CommonResult listInvoiceInfoByCashierIdAndDate(DailySummaryParam dailySummaryParam); @Override CommonResult getFirstSummaryDate(Integer cashierId);  }### Answer:
@Test public void testGetFirstSummaryDate() throws Exception { }