old_contents: 
  var express = require('..');
  var app = express();
  
  // number of middleware
  
  var n = parseInt(process.env.MW || '1', 10);
  console.log('  %s middleware', n);
  
  while (n--) {
    app.use(function(req, res, next){
      next();
    });
  }
  
  app.use(function(req, res, next){
    res.send('Hello World')
  });
  
  app.listen(3333);
  
new_contents: 
  var express = require('..');
  var app = express();
  
  // number of middleware
  
  var n = parseInt(process.env.MW || '1', 10);
  console.log('  %s middleware', n);
  
  while (n--) {
    app.use(function(req, res, next){
      next();
    });
  }
  
  app.use(function(req, res){
    res.send('Hello World')
  });
  
  app.listen(3333);
  
subject: remove unused parameter