odoo.define("myfirstwidget_test_js",function (require) {

    "use strict";

    var Class = require('web.Class');

​

    var Animal = Class.extend({

        init: function () {

            this.x = 0;

            this.hunger = 0;

        },

        move: function () {

            this.x = this.x + 1;

            this.hunger = this.hunger + 1;

        },

        eat: function () {

            this.hunger = 0;

        },

    });

    return Animal

});

//

odoo.define("myfirstwidget_test2_js",function (require) {

    "use strict";

    var Animal = require('myfirstwidget_test_js');

    var Dog = Animal.extend({

        move: function () {

            this.bark();

            this._super.apply(this, arguments);

        },

        bark: function () {

            console.log('woof');

        },

    });

    var dog = new Dog();

    dog.move()

});

​

odoo.define("myfirstwidget_test3_js",function (require) {

    "use strict";

    var Animal = require('myfirstwidget_test_js');

    var DanceMixin = {

    dance: function () {

        console.log('dancing...');

    },

};

​

    var Hamster = Animal.extend(DanceMixin, {

        sleep: function () {

            console.log('sleeping');

        },

    });

    var ham =  new   Hamster();

    ham.sleep();

    ham.dance();

    return Hamster

});

​

​

odoo.define("myfirstwidget_test4_js",function (require) {

    "use strict";

    var Hamster = require('myfirstwidget_test3_js');

    Hamster.include({

        sleep: function () {

            this._super.apply(this, arguments);

            console.log('zzzz');

        },

    });

    var ham =  new   Hamster();

    ham.sleep();

    ham.dance();

});