Model Extension in Appcelerator Alloy

index.js

var modelOne = Alloy.createModel('modelOne');
var modelTwo = Alloy.createModel('modelTwo',{
	name: "Bert",
	description: "is the man",
	URL:"thisisawesome.com"
});

Ti.API.info(modelTwo.config);
modelTwo.save();

$.index.open();

modelOne.js

exports.definition = {
	config: {
		columns: {
		    "name": "string",
		    "description": "string"
		},
		adapter: {
			type: "sql",
			collection_name: "modelOne"
		}
	},
	extendModel: function(Model) { 
		_.extend(Model.prototype, {
			// extended functions and properties go here
		});

		return Model;
	},
	extendCollection: function(Collection) {
		_.extend(Collection.prototype, {
			// extended functions and properties go here

			// For Backbone v1.1.2, uncomment the following to override the
			// fetch method to account for a breaking change in Backbone.
			/*
			fetch: function(options) {
				options = options ? _.clone(options) : {};
				options.reset = true;
				return Backbone.Collection.prototype.fetch.call(this, options);
			}
			*/
		});

		return Collection;
	}
};

modelTwo.js

var Alloy = require('alloy');
var baseModel = Alloy.createModel('test');
Ti.API.info( baseModel.config);

exports.definition = {
    config: {
    	columns: _.extend(baseModel.config.columns, {
    		"URL": "string"
    	}),
    	adapter: {
			type: "sql",
			collection_name: "test2"
		}
	}, 
    extendModel: function() {
    	Ti.API.info('EXTEND MODEL');
        var model = _.clone(baseModel.prototype); 
        _.extend(model, {
            // your props/methods here
        });
        return model
    } 
};