javascript - backbone - how to get the model when listening to "add" event on the collection

Question

first question here at SO :) I'm workin on a backbone project and the main example I rely on is TODOMVC by Addy Osmani, but there's something I cant figure out:

on the Todo app inside AppView

this.listenTo(app.Todos, 'add', this.addOne);

calls

addOne: function (todo) {
            var view = new app.TodoView({ model: todo });
            $('#todo-list').append(view.render().el);
        }

when I try to do the same I get the collection as the todo param inside addOne.

so, how can I get the actual model that was added?