Extend method copies properties from one object to another. Requires JavaScript 1.8.5+

Object.extend.js

Object.extend = function(toObj, fromObj){
    var p = Object.getOwnPropertyNames(fromObj),
        i = p.length;
    while(i--)
    {
        Object.defineProperty(toObj, p[i], Object.getOwnPropertyDescriptor(fromObj, p[i]));
    }
};