Nodejs Utililty Methods Array ForEach

Array.prototype.forEach = function(fun, thisp) {
  "use strict";
  if (this === void 0 || this === null) {
    throw new TypeError();
  var t = Object(this);
  var len = t.length >>> 0;
  if (typeof fun !== "function") {
    throw new TypeError();
...

Array.prototype.forEach = function(func)
  for(var i = 0, l = this.length; i < l; i ++)
    func(this[i]);
};

Array.prototype.forEach = function (func) {
    var length = this.length;
    for (var i = 0; i < length; i++) {
        func(this[i]);

Array.prototype.forEach = Array.prototype.forEach || (Array.prototype.forEach = function(func, thisObj) {
  for (var i=0, l=this.length; i<l; ++i) {
    func.call(thisObj, this[i], i, this);
  };
});

Array.prototype.forEach = function(iterator) {
  for (var i = 0, len = this.length; i < len; i++) {
    iterator(this[i], i);
};

Array.prototype.forEach = function(predicate)
  for (var i = 0; i < this.length; i++)
    predicate(this[i]);
Array.prototype.contains = function(o)
  return this.indexOf(o) >= 0;

items = document.querySelectorAll('x-markdown')
Array.prototype.forEach.call(items, (item)=>{
  html = marked(item.textContent)
  item.innerHTML = html
})

Array.prototype.forEach1 = function ( callback ) {
        for (var j = 0, k ; k=this[j++]; ) {  callback(k,j,this) ; }
Array.prototype.forEach2 = function ( callback ) {
        for (var j = 0 ; j < this.length; j++ ) {  callback(this[j],j,this) ; }
Array.prototype.forEach3 = function ( callback ) {
        var j = 0 ; while( this[j++] ) {  callback(this[j],j,this) ; }
var a = [1,2,3,4,5,6,7,8,9,0] ;
function unit ( method ) 
   var s = [] ;
    a[method]( function (v,i,a) { s.push(i+":"+v); } )
  return s ;
function loop ( size, method ) {
var t1 = new Date() ;
 while ( size--) { unit(method); }
return (new Date()) - t1 ;
loopall = function ( ) {
 var s = [] ;
 var j = 0, method ; while ( method = arguments[j++] ) {
  s.push( method + ": " +  loop( 1e4 , method )  + " ms " ) ;
   return s ;
} ( "forEach1", "forEach2", "forEach3" ) .join("\n") ;

Array.prototype.forEach2 = function (a) {
  for (var b = 0; b < this.length; ++b) a(this[b], b, this)
};
Array.prototype.map2 = function (a) {
  var l = this.length;
  var array = new Array(l),
    i = 0;
  for (; i < l; i++) {
    array[i] = a(this[i], i)
...

'use strict';
Array.prototype.forEachCallback = function(callback, finishCallback) {
  var current = 0;
  var self = this;
  var next = function() {
    if (!self) {
      console.log("Something went wrong...");
      throw('No self!');
      return;
...