code: function listener (event, done) {
    return function onevent (arg1) {
      var args = new Array(arguments.length)
      var ee = this
      var err = event === 'error'
        ? arg1
        : null
  
      // copy args to prevent arguments escaping scope
      for (var i = 0; i < args.length; i++) {
        args[i] = arguments[i]
      }
  
      done(err, ee, event, args)
    }
  }
docs: Create the event listener.
  @private