code: def head(self, url, *args, **kwargs):
          
          with LOG_JWS_HEAD().context():
              return DeferredContext(
                  self._send_request(u'HEAD', url, *args, **kwargs)
                  ).addActionFinish()
docs: Send HEAD request without checking the response.
  
          Note that ``_check_response`` is not called, as there will be no
          response body to check.
  
          :param str url: The URL to make the request to.