final File downloadDir = new File(config.getStringProperty(BackFillerConfig.DOWNLOAD_DIR));
downloadDir.mkdirs();
// connect the download service to the file manager.
FileManager fileManager = new CloudFilesManager(USER, KEY, PROVIDER, ZONE, CONTAINER, config.getIntegerProperty(BackFillerConfig.BATCH_SIZE));
DownloadService downloadService = new DownloadService(downloadDir);
downloadService.setFileManager(fileManager);
// delete any temp files before starting.
for (File tmp : downloadDir.listFiles(new FilenameFilter() {