Evaluate functions on object

Model.prototype.$extended

Model.prototype.$extended = function () {
    var thisModel = this,
        extendedModel = angular.copy(thisModel);

    Object
        .keys(thisModel)
        .filter(key => typeof thisModel[key] === 'function')
        .forEach(key => {
            try {
                extendedModel[key] = thisModel[key]();
            }
            catch (err) {
                // expected. some methods require arguments, so swallow.
            }
        })
    ;

    return extendedModel;
};