Ember.computed.filter crashes obsevring an array

[estshy]

Let's start with working demo: http://jsbin.com/monanipiwe/1/

App = Ember.Application.create();

var first = Ember.Object.create({
  name: 'first',
  id: 1
});

var second = Ember.Object.create({
  name: 'second',
  id: 2
});

App.ApplicationRoute = Ember.Route.extend({
  model: function() {
    return [first, second];
  }
});

App.ApplicationController = Ember.ArrayController.extend({
  showOnlyWithIds: [1,2,3,4,5,6],
  filteredModel: Ember.computed.filter('@this', function(item) {
    return item.get('name');
  }).property('@this')
});

Inside controller I have some ids that are observed by function line below. I am going to use it to filter model.

App.ApplicationController = Ember.ArrayController.extend({
  showOnlyWithIds: [1,2,3,4,5,6],
  filteredModel: Ember.computed.filter('@this', function(item) {
    return item.get('name');
  }).property('@this', 'showOnlyWithIds')
}); 

But wait... I can't.

TypeError: item.get is not a function

I don't understand why but each item of showOnlyWithIds is passed as parameter to callback. Why?

[wagenet]

Grouping with #9462