### Question:
PaymentServiceImpl implements PaymentService { @Override @Transactional public CommonResult updateTransactionLogsAsPaid(List<TransactionParam> transactionParams) { String newInvoiceCode; synchronized (this) { CommonResult result = invoiceService.getNextInvoiceCode(); newInvoiceCode = (String) result.getData(); } int count = 0; for (TransactionParam transactionParam : transactionParams) { if(transactionParam.getStatus() == 1){ Integer collectionId = transactionParam.getCollectionId(); Integer projectId = transactionParam.getProjectId(); List<TransactionLog> detailedLogs = transactionLogMapper.listItemsByCollectionIdAndProjectId(collectionId, projectId); for(TransactionLog t: detailedLogs){ t.setInvoiceCode(newInvoiceCode); t.setCashierId(transactionParam.getCashierId()); t.setStatus((byte)2); count += transactionLogMapper.update(t); } } } if (count > 0){ invoiceService.updateStatus((byte)3, newInvoiceCode); return CommonResult.success(newInvoiceCode); } return CommonResult.fail(E_700); }  @Override CommonResult listTransactionLogsByRegistrationId(Integer registrationId); @Override CommonResult listTransactionLogsByInvoiceCode(String invoiceCode); @Override CommonResult listTransactionLogsByCollectionAndProjectId(Integer collectionId, Integer projectId); @Override @Transactional CommonResult updateTransactionLogsAsPaid(List<TransactionParam> transactionParams); @Override CommonResult updateTransactionLogsAsReturned(List<TransactionParam> transactionLogParams); @Override CommonResult reprintTransactionLog(String invoiceCode, Integer newCashierId); @Override CommonResult listLogsByRegistrationIdAndDate(Integer registrationId, String beginDateStr, String endDateStr);  }### Answer:
@Test public void testUpdateTransactionLogsAsPaid() throws Exception { }