### Question:
InvoiceServiceImpl implements InvoiceService { @Override public CommonResult insertInvoices(String beginInvoiceCode, String endInvoiceCode){ BigDecimal begin = new BigDecimal(beginInvoiceCode); BigDecimal end = new BigDecimal(endInvoiceCode); int count = 0; while(begin.compareTo(end) != 1){ count += invoiceMapper.insert(begin.toString()); begin = begin.add(BigDecimal.valueOf(1)); } if(count > 0) return CommonResult.success(count); else return CommonResult.fail(); }  @Override synchronized CommonResult getNextInvoiceCode(); @Override CommonResult updateStatus(Byte status, String invoiceCode); @Override CommonResult insertInvoices(String beginInvoiceCode, String endInvoiceCode); @Override CommonResult getInvoiceInfo(); @Override CommonResult list();  }### Answer:
@Test public void testInsertInvoices() throws Exception { }