code: function createApplication() {
    var app = function(req, res, next) {
      app.handle(req, res, next);
    };
  
    mixin(app, EventEmitter.prototype, false);
    mixin(app, proto, false);
  
    // expose the prototype that will get set on requests
    app.request = Object.create(req, {
      app: { configurable: true, enumerable: true, writable: true, value: app }
    })
  
    // expose the prototype that will get set on responses
    app.response = Object.create(res, {
      app: { configurable: true, enumerable: true, writable: true, value: app }
    })
  
    app.init();
    return app;
  }
docs: Create an express application.
  
  @return {Function}
  @api public