If the message has a loaded web preview,
        this returns the :tl:`WebPage` object.

def web_preview(self):
        """
        If the message has a loaded web preview,
        this returns the :tl:`WebPage` object.
        """
        if isinstance(self.media, types.MessageMediaWebPage):
            if isinstance(self.media.webpage, types.WebPage):
                return self.media.webpage