code: function retry(response) {
          var retryAfter = response.headers['retry-after'];
          if (typeof retryFn === 'function' && retryAfter) {
              retryAfter = parseInt(retryAfter, 10);
              setTimeout(retryFn, retryAfter * 1000);
              return true;
          }
          return false;
      }
docs: Retry the request if a retry function and retry-after headers are present
  @param   {HTTPResponse} response The response object
  @returns {void}