/**
  * @covers WPSEO_Twitter::url
  */
 public function test_twitter_url()
 {
     // create and go to post
     $post_id = $this->factory->post->create();
     $this->go_to(get_permalink($post_id));
     $expected = $this->metatag('url', esc_url(WPSEO_Frontend::get_instance()->canonical(false)));
     self::$class_instance->url();
     $this->expectOutput($expected);
 }
 public function url()
 {
     return parent::url();
 }