code: public static void writeBook(Workbook book, OutputStream out) throws IORuntimeException {
  		try {
  			book.write(out);
  		} catch (IOException e) {
  			throw new IORuntimeException(e);
  		}
  	}
docs: 将Excel Workbook刷出到输出流，不关闭流
  
  @param book {@link Workbook}
  @param out 输出流
  @throws IORuntimeException IO异常
  @since 3.2.0