old_contents: var http = require('http');
  var url = require('url');
  var request = require('request');
  var qs = require('qs');
  
  var API_TOKEN = process.env.API_TOKEN;
  var IP = process.env.IP || "localhost";
  var PORT = process.env.PORT || 7777;
  
  if (!API_TOKEN) {
    console.error("API_TOKEN=your_token_here node %s", __filename);
    console.error("https://developer.uber.com/v1/tutorials/#server-side-authentication");
  }
  
  http.createServer(function (req, res) {
    var url_parts = url.parse(req.url, true);
    if (url_parts.pathname === '/favicon.ico') {
      res.writeHead(404);
      res.end();
      return;
    };
  
    if (!url_parts.query.latitude || !url_parts.query.longitude) {
      res.writeHead(408, {'Content-Type': 'application/json'});
      res.end(JSON.stringify({
        "message": "Missing parameters: latitude, longitude."
      }));
      return;
    };
  
    var params = {
      'server_token': API_TOKEN,
      'start_latitude': url_parts.query.latitude,
      'start_longitude': url_parts.query.longitude
    };
  
    var request_url = "https://api.uber.com/v1/estimates/time?" +
                      qs.stringify(params);
  
    request.get({url: request_url},
      function (error, response, body) {
        if (response.statusCode != 200) {
          res.writeHead(response.statusCode,
                       {'Content-Type': 'application/json'});
          res.end(body);
          return;
        }
  
        res.writeHead(200, {'Content-Type': 'application/json'});
        res.end(body);
    });
  }).listen(PORT, IP);
  
  console.log('Server running at http://%s:%s', IP, PORT);
new_contents: var http = require('http');
  var url = require('url');
  var request = require('request');
  var qs = require('qs');
  
  var API_TOKEN = process.env.API_TOKEN;
  var IP = process.env.IP || "localhost";
  var PORT = process.env.PORT || 7777;
  
  if (!API_TOKEN) {
    console.error("API_TOKEN=your_token_here node %s", __filename);
    console.error("https://developer.uber.com/v1/tutorials/#server-side-authentication");
    process.exit(1);
  }
  
  http.createServer(function (req, res) {
    var url_parts = url.parse(req.url, true);
    if (url_parts.pathname === '/favicon.ico') {
      res.writeHead(404);
      res.end();
      return;
    };
  
    if (!url_parts.query.latitude || !url_parts.query.longitude) {
      res.writeHead(408, {'Content-Type': 'application/json'});
      res.end(JSON.stringify({
        "message": "Missing parameters: latitude, longitude."
      }));
      return;
    };
  
    var params = {
      'server_token': API_TOKEN,
      'start_latitude': url_parts.query.latitude,
      'start_longitude': url_parts.query.longitude
    };
  
    var request_url = "https://api.uber.com/v1/estimates/time?" +
                      qs.stringify(params);
  
    request.get({url: request_url},
      function (error, response, body) {
        if (response.statusCode != 200) {
          res.writeHead(response.statusCode,
                       {'Content-Type': 'application/json'});
          res.end(body);
          return;
        }
  
        res.writeHead(200, {'Content-Type': 'application/json'});
        res.end(body);
    });
  }).listen(PORT, IP);
  
  console.log('Server running at http://%s:%s', IP, PORT);
subject: Add process.exit