code: function processResponse(err, res, body) {
  
      if (err) { return cb(err); }
  
      if (res.statusCode !== 200) {
        return cb(new ScrapeError('Not OK response from server.', res, body));
      }
  
      parseBody(body, model, options, cb);
  
    }
docs: Handle `request()`'s result: Chain `err` or proceed to parse the resource.