SOURCE

'use strict'

function extend(sub, sup) {
  var F = function();
  F.prototype = sup.prototype;
  sub.prototype = new F();
  sub.prototype.constructor = sub;
	
  sub.supclass = sup.prototype;
  if (sup.prototype.constructor == Object.prototype.constructor) {
    sup.prototype.constructor = sup;
  }
}

var F = function () {
  
};

F.prototype = {
  
};
console.log(new F());