bin/express-cli.js
function around (obj, method, fn) {
  var old = obj[method]

  obj[method] = function () {
    var args = new Array(arguments.length)
    for (var i = 0; i < args.length; i++) args[i] = arguments[i]
    return fn.call(this, old, args)
  }
}
function around (obj, method, fn) {
  var old = obj[method]

  obj[method] = function () {
    var args = new Array(arguments.length)
    for (var i = 0; i < args.length; i++) args[i] = arguments[i]
    return fn.call(this, old, args)
  }
}
Install an around function; AOP.