在Backbone.js集合中记录更改，我的集合未定义

嘿！我是Backbone.js的新手，所以这个问题很可能很简单。

每次我的好友收藏发生变化时，我都想安慰一下。因此，我在集合中绑定了all事件来调用我的logFunction。。但是在logfunction中CCD_ 2是未定义的。为什么？

这是我的"应用程序"：

(function ($) {

       Friend = Backbone.Model.extend({
           //Create a model to hold friend atribute
           name: null
       });

       Friends = Backbone.Collection.extend({
           model: Friend,
           //This is our Friends collection and holds our Friend models
           initialize: function (models, options) {
               this.bind("add", options.view.addFriendLi);
               this.bind("all", options.view.logFriendsCollection);
               //Listen for new additions to the collection and call a view function if so
           }
       });
       window.AppView = Backbone.View.extend({
           el: $("body"),
           initialize: function () {
               this.friends = new Friends(null, { view: this });
           },
           events: {
               "click #add-friend": "showPrompt"
           },

           showPrompt: function () {
               var friend_name = prompt("Who is your friend?");
               var friend_model = new Friend({ "name": friend_name });
               this.friends.add(friend_model);
           },
           addFriendLi: function (model) {
               $("#friends-list").append("<li>" + model.get('name') + "</li>");
           },
           logFriendsCollection: function (args) {
               console.log("Friends", this.friends);
           }
       }); var appview = new AppView;