polyTest.js

(function() {

    var defineProperty = 'defineProperty' in Object,
        defineGetter = '__defineGetter__' in Object;
            
    // mini polyfill for defining getters
    Object.extend({
        defineGetter: function(object, prop, fn) {
   
            if (defineProperty) {
                // console.log('defineProperty available');
                Object.defineProperty(object, prop, {
                    get: fn,
                    enumerable: false
                }); 
            }
            else if (defineGetter) {
                // console.log('__defineGetter__ available');
                object.__defineGetter__(prop, fn);
            }
            else {
                // fallback is a function for really old browsers.
                object[prop] = fn;
            }
            
        }
    });

}());