Use the Rest Operator with Function Parameters- help!

Tell us what’s happening:

Im confused on why this isn’t working. I did watch the video and that made more sense to me than the explanation here- as I understand it, the difference would just be that this is a passed function so I think I should be able to write this as:

function renamedFunction(x,y,z){
console.log (x+y+z)

var args = [0,1,2,3];

Your code so far

const sum = (function() {
  "use strict";
  return function sum(... z) {
    return z.reduce((a, b) => a + b, 0);
console.log(sum(1, 2, 3)); // 6

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User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36.

Link to the challenge:

Replace z with args.

Note, when something is color coded red in the assignment text, or the test assertions, it is a value and should be taken literally.