Cross-browser object.watch and unwatch. Modified for use with MooTools and MooTools More

object-watch.js

// Cross-browser object.watch and object.unwatch
// Requires Mootools 1.4 or greater

// object.watch
(function(){
	if (!Object.prototype.watch) {
		Object.implement('watch',function(prop,handler){
			var oldval = this[prop], newval = oldval,
			getter = function () {
				return newval;
			},
			setter = function (val) {
				oldval = newval;
				return newval = handler.call(this, prop, oldval, val);
			};
			if (delete this[prop]) { // can't watch constants
				if (Object.defineProperty) { // ECMAScript 5
					Object.defineProperty(this, prop, {
						get: getter,
						set: setter,
						enumerable: false,
						configurable: true
					});
				} else if (Object.prototype.__defineGetter__ && Object.prototype.__defineSetter__) { // legacy
					Object.prototype.__defineGetter__.call(this, prop, getter);
					Object.prototype.__defineSetter__.call(this, prop, setter);
				}
			}
		});
		
		Object.prototype.watch.extend('include',function(){return});
		Object.prototype.watch.extend('split',function(){return});

	};

	// object.unwatch
	if (!Object.prototype.unwatch) {
		Object.implement('unwatch',function (prop) {
			var val = this[prop];
			delete this[prop]; // remove accessors
			this[prop] = val;
		});
		
		Object.prototype.unwatch.extend('include',function(){return});
		Object.prototype.unwatch.extend('split',function(){return});
	};
})();

sorry for the question, but how to use? It's need only pure Javascript?