Nodejs Utililty Methods Array Push Unique

Array.prototype.pushIfUnique = function(entryIn){
    var arr = this;
    var unique = true;
    arr.forEach(function(entry){
        if(entryIn === entry){
            unique = false;
    });
    if(unique){
...

Array.prototype.pushUniq = function(el, test) {
    if (test == null) {
        if (this.indexOf(el) < 0) {
            this.push(el);
            return true;
        return false;
    for (var i = this.length; --i >= 0;)
...

Array.prototype.pushUnique = function(item){
    if(this.indexOf(item) === -1) this.push(item);

Array.prototype.pushUnique = function (item){
    if(this.indexOf(item) === -1) {
        this.push(item);
        return true;
    return false;
};

Array.prototype.pushUnique = function (item) {
    if (this.indexOf(item) == -1) {
        this.push(item);
        return true;
    return false;
};
String.prototype.repeat = function (num) {
    return new Array(num + 1).join(this);
...

Array.prototype.pushUnique = function(item,unique)
  if(unique === false) {
    this.push(item);
  } else {
    if(this.indexOf(item) == -1)
      this.push(item);
};
...

Array.prototype.pushUnique = function(k, v) {
  exist = false;
  for(var i = 0; i < this.length; i++) {
    if (this[i][k] == v) return this[i];
  if (!exist) {
    obj = {};
    obj[k] = v;
    this.push(obj);
...

Array.prototype.pushUnique=function(obj){
  if(this.containsObject(obj)){
    return;
  this.push(obj);

Array.prototype.pushUnique = function (obj, equalityFunction) {
  equalityFunction  = (typeof equalityFunction === "undefined") ? function(a, b) { return a === b } : equalityFunction;
  for(var n = 0; n < this.length; n++) {
    if(equalityFunction(this[n], obj)) { 
      return false;
  this.push(obj);
  return true;
...

Array.prototype.pushUnique = function(value) {
    if (this.include(value)) return this;
    this.push(value);
    return this;
Array.prototype.concatUnique = function(arr) {
    for (index in arr) {
        if (typeof arr[index] != "function") this.pushUnique(arr[index]);
    return this;