def cleanup(self):
        """Move cached elements to top."""
        self.num_puts = 0
        cached = []
        for i, url_data in enumerate(self.queue):
            key = url_data.cache_url
            cache = url_data.aggregate.result_cache
            if cache.has_result(key):
                cached.append(i)
        for pos in cached:
            self._move_to_top(pos)
Move cached elements to top.