/**
  * @covers WPSEO_Twitter::site_domain
  */
 public function test_author_twitter()
 {
     $name = 'yoast';
     $expected = $this->metatag('creator', '@' . $name);
     // test option
     self::$class_instance->options['twitter_site'] = $name;
     self::$class_instance->author_twitter();
     $this->expectOutput($expected);
     // reset option to make sure next result is from author meta
     self::$class_instance->options['twitter_site'] = '';
     /*
      TODO fix this part
     
     // create post, attach user as author
     $user_id = $this->factory->user->create( array( 'role' => 'administrator' ) );
     $post_id = $this->factory->post->create(
     	array(
     		'post_title' => 'Sample Post',
     		'post_type' => 'post',
     		'post_status' => 'publish',
     	)
     );
     
     // go to post we just created
     $this->go_to( get_permalink( $post_id ) );
     
     // test user meta
     update_user_meta( $this->user_id, 'twitter', '@' . $name );
     self::$class_instance->author_twitter();
     $this->expectOutput( $expected );
     */
 }