WPSEO_OpenGraph::tags PHP Méthode

    public function tags()
    {
        if (!is_singular()) {
            return false;
        }
        $tags = get_the_tags();
        if (!is_wp_error($tags) && (is_array($tags) && $tags !== array())) {
            foreach ($tags as $tag) {
                $this->og_tag('article:tag', $tag->name);
            }
            return true;
        }
        return false;
    }

 /**
  * @covers WPSEO_OpenGraph::tags
  */
 public function test_tags()
 {
     // not singular, return false
     $this->assertFalse(self::$class_instance->tags());
     // create post, without tags
     $post_id = $this->factory->post->create();
     $this->go_to(get_permalink($post_id));
     // no tags, should return false
     $this->assertFalse(self::$class_instance->tags());
     // add tags to post
     wp_set_post_tags($post_id, 'Tag1, Tag2');
     $expected_tags = '<meta property="article:tag" content="Tag1" />' . "\n" . '<meta property="article:tag" content="Tag2" />' . "\n";
     // test again, this time with tags
     $this->assertTrue(self::$class_instance->tags());
     $this->expectOutput($expected_tags);
 }