var Singleton = (function() {
    var private_property = 0,
        private_method = function () {
            console.log('This is private');
        }
    
    return {
        prop: 1,
        another_prop: 'value',
        method: function() {
            private_method();
            return private_property;
        },
        another_method: function() {…}
    }
}());