text: // Returns a wrapper function that returns a wrapped callback
  // The wrapper function should do some stuff, and return a
  // presumably different callback function.
  // This makes sure that own properties are retained, so that
  // decorations and such are not lost along the way.
  module.exports = wrappy
  function wrappy (fn, cb) {
    if (fn && cb) return wrappy(fn)(cb)
  
    if (typeof fn !== 'function')
      throw new TypeError('need wrapper function')
  
    Object.keys(fn).forEach(function (k) {
      wrapper[k] = fn[k]
    })
  
    return wrapper
  
    function wrapper() {
      var args = new Array(arguments.length)
      for (var i = 0; i < args.length; i++) {
        args[i] = arguments[i]
      }
      var ret = fn.apply(this, args)
      var cb = args[args.length-1]
      if (typeof ret === 'function' && ret !== cb) {
        Object.keys(cb).forEach(function (k) {
          ret[k] = cb[k]
        })
      }
      return ret
    }
  }
  