adding .extend()

found .extend() in node.js

Object.defineProperty(Object.prototype, "extend", {
    enumerable: false,
    value: function(from) {
        var props = Object.getOwnPropertyNames(from);
        var dest = this;
        props.forEach(function(name) {
            if (name in dest) {
                var destination = Object.getOwnPropertyDescriptor(from, name);
                Object.defineProperty(dest, name, destination);
            }
        });
        return this;
    }
});

//usage:
var foo = {'a':1,'b':2};
var bar = {'a':3};
console.log(foo.extend(bar));
// {'a':3,'b':2}