Suin\RSSWriter\Item::guid PHP Method

    public function guid($guid, $isPermalink = false)
    {
        $this->guid = $guid;
        $this->isPermalink = $isPermalink;
        return $this;
    }

 public function testGuid_with_permalink()
 {
     $item = new Item();
     $item->guid('guid', true);
     $this->assertAttributeSame(true, 'isPermalink', $item);
     $item->guid('guid', false);
     $this->assertAttributeSame(false, 'isPermalink', $item);
     $item->guid('guid');
     // default
     $this->assertAttributeSame(false, 'isPermalink', $item);
 }