private InputStream downloadFile(String fileName) throws IOException {
    File file = DriveUtil.getFileByName(fileName);

    if (file.getDownloadUrl() != null && file.getDownloadUrl().length() > 0)
      try {
        fileSize = file.getFileSize();
        return DriveUtil.service.files().get(file.getId()).executeMediaAsInputStream();
      } catch (IOException e) {
        e.printStackTrace();
        MAMUtil.writeLog(e);
        return null;
      }

    return null;
  }