gistfile1.js

var Widget = new Class({
    Implements: Options,
    options: {
        color: '#fff',
        size: {
            width: 100,
            height: 100
        }
    },
    initialize: function(options){
        this.setOptions(options);
    }
});
 
var myWidget = new Widget({
    color: '#f00',
    size: {
        width: 200
    }
});