Extjs类的动态加载时碰到有关问题求解

Extjs类的动态加载时碰到问题求解
我在学习Extjs类的动态加载时，碰到一个问题，求解啊
问题如下：在webroot/src/Cookbook文件夹中有两个类Vehicle和Plane
Vehicle.js代码如下：
Ext.define('Cookbook.Vehicle', {
                                                config : {
                                                        manufacturer : 'UnKown Manufacturer',
                                                        model : 'UnKown Model',
                                                        topSpeed : 0
                                                },

                                                constructor : function(manufacturer, model, topSpeed) {
                                                        this.initConfig();
                                                        if (manufacturer)
                                                                this.setManufacturer(manufacturer);
                                                        if (model)
                                                                this.setModel(model);