Nodejs Utililty Methods Array Push Unique

Array.prototype.pushUniquely = function(e){
  for(var i=0;i<this.length;i++){
    var ae = this[i];
    if(ae instanceof Array && e instanceof Array){
      if(ae.isEqual(e)) return i;
    }else{
      if(ae==e) return i;
  return this.push(e)-1;

Array.prototype.pushReplace = function(pattern){
  var args = Array.prototype.slice.call(arguments, 1);
  this.push(pattern.replace(/\{(\d+)\}/g, function(pattern, index){
    return args[index].toString();
  }));
  return this;
};

Array.prototype.push_unique = function (value) {
  if (!this.in_array(value)) {
      this.push(value);
};