def entry_links(self):
        """ Given a parsed feed, return the links to its entries, including ones
        which disappeared (as a quick-and-dirty way to support deletions)
        """
        return {entry['link'] for entry in self.feed.entries if entry and entry.get('link')}
Given a parsed feed, return the links to its entries, including ones
        which disappeared (as a quick-and-dirty way to support deletions)