Get the absolute url of ``self``.

        Returns:
            str: the absolute url.

def absolute_url(self):
        """Get the absolute url of ``self``.

        Returns:
            str: the absolute url.
        """
        if self.is_root():
            return utils.concat_urls(self.url)
        return utils.concat_urls(self.parent.absolute_url, self.url)