code: function long(callback) {
    var called = false
  
    return function cbOnceLater() {
      var args
  
      if (called) {
        return
      }
  
      called = true
      args = Array.prototype.slice.call(arguments)
  
      process.nextTick(function () {
        callback.apply(null, args)
      })
    }
  }
docs: Slower, uncommon version