code: function createStack(app) {
    if (!app) {
      throw new Error("Pack-n-stack requires an express/connect app");
    };
    
    app = utils.merge(app, proto);
  
    Object.defineProperty(app, "count", {
      get: function() {
        return app.stack.length;
      }
    });
  
    return app;
  }
docs: Create a new stack.
  
  @return {Function}
  @api public