title: ExpressJS: Append header to incoming request object
body: <p>I'm trying to append additional header to an incoming request, it can't seem to work. </p>
  
  <pre><code>server.get('/', function md1(req, res, next) {
      req.setHeader('px-test-header', 1234); // Error - "req.setHeader is not a function"
      req.headers['px-test-header'] = 1234; // nothing happens
   }, function (req, res, next) {
      console.log(req.get('px-test-header')); // always undefined
  }, handler);
  </code></pre>
  
  <p>What am I doing wrong? Is it even possible? </p>
  
  <p>Note - I do not want to modify the request object with additional parameter instead.</p>