beforeEach: function() {
    content = Ember.A([
      Ember.Object.create({location: locations.nyc}),
      Ember.Object.create({location: locations.sf}),
      Ember.Object.create({location: locations.chicago}),
      Ember.Object.create({location: null})
    ]);

    var collectionClass = MarkerCollectionLayer.extend({
      content: content
    });

    component = this.subject();
    component.set('childLayers', [collectionClass]);

    this.render();

    collection = component._childLayers[0];
  }
  beforeEach: function() {
    content = Ember.A([
      Ember.Object.create({location: locations.nyc}),
      Ember.Object.create({location: locations.sf}),
      Ember.Object.create({location: locations.chicago}),
      Ember.Object.create({location: null})
    ]);

    controller = Ember.ArrayProxy.create({
      content: content
    });
    var collectionClass = MarkerCollectionLayer.extend({
      contentBinding: 'controller'
    });
    component = this.subject();
    component.setProperties({
      controller: controller,
      childLayers: [collectionClass]
    });

    this.render();

    collection = component._childLayers[0];
  }