code: def _download_item(item_id, path='.', item=None):
      
      session.token = verify_credentials()
  
      filename, content_iter = session.communicator.download_item(
          item_id, session.token)
      item_path = os.path.join(path, filename)
      print('Creating file at {0}'.format(item_path))
      out_file = open(item_path, 'wb')
      for block in content_iter:
          out_file.write(block)
      out_file.close()
      for callback in session.item_download_callbacks:
          if not item:
              item = session.communicator.item_get(session.token, item_id)
          callback(session.communicator, session.token, item, item_path)
docs: Download the requested item to the specified path.
  
      :param item_id: The id of the item to be downloaded
      :type item_id: int | long
      :param path: (optional) the location to download the item
      :type path: string
      :param item: The dict of item info
      :type item: dict | None