code: def download_raw(url, local_path, callback):
      
      log.debug('download_raw(url={url}, local_path={local_path})'.format(url=url, local_path=local_path))
      raw_progress = RawDownloadProgress(callback)
      reporthook = raw_progress.get_report_hook()
      try:
          log.debug('urlretrieve(url={url}, local_path={local_path}) ...'.format(url=url, local_path=local_path))
          urlretrieve(url=url, filename=local_path, reporthook=reporthook)
          log.debug('... SUCCEEDED')
          callback.finish(True)
          return True
      except URLError:
          log.exception('... FAILED')
          callback.finish(False)
          return False
docs: Download an url to a local file.
      :param url: url of the file to download
      :param local_path: path where the downloaded file should be saved
      :param callback: instance of ProgressCallback
      :return: True is succeeded