code: function (req, res, next) {
      var graphApiUrl = 'https://graph.facebook.com/me';
      var accessToken = req.accessToken;
  
      request.get({ url: graphApiUrl, qs: accessToken, json: true }, function(err, response, profile) {
        if (response.statusCode !== 200) {
          res.status(500).send({ message: profile.error.message });
          return;
        }
        req.profile = profile;
        next();
      });
    }
docs: Step 2. Retrieve profile information about the current user.