code: function(arr) {
        if (arr === undefined) { arr = []; }
        return EmberArray.detect(arr) ? arr : NativeArray.apply(arr);
      }
docs: Creates an `Ember.NativeArray` from an Array like object.
  Does not modify the original object. Ember.A is not needed if
  `Ember.EXTEND_PROTOTYPES` is `true` (the default value). However,
  it is recommended that you use Ember.A when creating addons for
  ember or when you can not guarantee that `Ember.EXTEND_PROTOTYPES`
  will be `true`.
  
  Example
  
  ```js
  var Pagination = Ember.CollectionView.extend({
  tagName: 'ul',
  classNames: ['pagination'],
  
  init: function() {
  this._super();
  if (!this.get('content')) {
  this.set('content', Ember.A());
  }
  }
  });
  ```
  
  @method A
  @for Ember
  @return {Ember.NativeArray}