title: How to make web service calls in Expressjs?
body: <pre><code>app.get('/', function(req, res){
  
  var options = {
    host: 'www.google.com'
  };
  
  http.get(options, function(http_res) {
      http_res.on('data', function (chunk) {
          res.send('BODY: ' + chunk);
      });
      res.end("");
  });
  </code></pre>
  
  <p>});</p>
  
  <p>I am trying to download google.com homepage, and reprint it, but I get an "Can't use mutable header APIs after sent." error</p>
  
  <p>Anyone know why? or how to make http call?</p>