Nodejs Object Value Set addSibling(k, v)

Here you can find the source of addSibling(k, v)

Method Source Code

Object.prototype.addSibling = function(k, v) {
   if (typeof this[k] === 'undefined') this[k] = v;
   return this[k];
}

Object.prototype.setDefault = function(key, value) {
    if (!this.hasOwnProperty(key)) {
  this[key] = value;
    return this[key];
};