code: def download_item(self, item_id, token=None, revision=None):
          
          parameters = dict()
          parameters['id'] = item_id
          if token:
              parameters['token'] = token
          if revision:
              parameters['revision'] = revision
          method_url = self.full_url + 'midas.item.download'
          request = requests.get(method_url,
                                 params=parameters,
                                 stream=True,
                                 verify=self._verify_ssl_certificate)
          filename = request.headers['content-disposition'][21:].strip('"')
          return filename, request.iter_content(chunk_size=10 * 1024)
docs: Download an item to disk.
  
          :param item_id: The id of the item to be downloaded.
          :type item_id: int | long
          :param token: (optional) The authentication token of the user
              requesting the download.
          :type token: None | string
          :param revision: (optional) The revision of the item to download, this
              defaults to HEAD.
          :type revision: None | int | long
          :returns: A tuple of the filename and the content iterator.
          :rtype: (string, unknown)