def image_size(self) -> Optional[int]:
        r"""(:class:`~typing.Optional`\ [:class:`int`]) The size of the image
        in bytes.  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]['size']
        return None