public function testAddCustomMediaItemFieldWithItemInterface()
{
$fakeEntityWithMedias = new FakeItemInterfaceEntity();
$fakeEntityWithMedias->setFeedMediaItem(['type' => 'image/jpeg', 'length' => 500, 'value' => 'http://website.com/image.jpg']);
$fakeEntityNoMedias = new FakeItemInterfaceEntity();
$feed = $this->manager->get('article');
$feed->add($fakeEntityWithMedias);
$feed->add($fakeEntityNoMedias);
$feed->addItemField(new MediaItemField('getFeedMediaItem'));
$output = $feed->render('rss');
$this->assertContains('<enclosure url="http://website.com/image.jpg" type="image/jpeg" length="500"/>', $output);
}