Backbone Collection URL未定义

Question

尝试将url传递给fetchFromURL函数，但在登录时未定义URL。不知道为什么会发生这种情况!!

class Device extends Backbone.Model

class Devices extends Backbone.Collection
    model: Device
    localStorage: new Backbone.LocalStorage 'devices'
    url: "http://192.168.2.17:8030/profile/RestProfile.svc/GetDeviceList/"
    fetchFromURL: =>
        collection = @
        console.log @url

getView = =>
    devices = new Devices
    devices.fetch()
    devices.fetchFromURL()