code: def cleanup(self):
          
          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)
docs: Move cached elements to top.