code: public static XlsxWorkbook getWorkbook(InputStream stream) throws IOException
      {
          try
          {
              return new XlsxWorkbook(stream);
          }
          catch(Docx4JException e)
          {
              throw new IOException(e);
          }
      }
docs: Returns an existing workbook object.
  @param stream The stream with the workbook
  @return The existing workbook object
  @throws IOException if the stream cannot be read