def image_url(self) -> Optional[str]:
        r"""(:class:`~typing.Optional`\ [:class:`str`]) The image url.
        It may be :const:`None` if it's not an image.

        """
        images = self.attributes.get('imageinfo', [])
        if images and isinstance(images, collections.abc.Sequence):
            return images[0]['url']
        return None