function testPreviewWithCustomMoreTag()
 {
     $pid = $this->factory->post->create(array('post_content' => 'Eric is a polar bear <!-- more But what is Elaina? --> Lauren is not a duck', 'post_excerpt' => ''));
     $post = new TimberPost($pid);
     $this->assertEquals('Eric is a polar bear <a href="' . $post->link() . '" class="read-more">But what is Elaina?</a>', $post->preview());
 }