var Package = {};

Package.Class = Class.create();
Object.extend(Package.Class.prototype, {
    initialize: function(options) {
        this.options = options;
    },

// ...
});

Package.Subclass = Class.create();
Object.extend(Package.Subclass.prototype, Object.extend(Package.Class, {
    initialize: function(menu) {
        this.menu = menu; 
        this.options = menu.options; 
    },

// ...
}));