def remove_old_entries(self, created_before):
        """ Deletes entries from cache with creation time older than ``created_before``
        """
        keys_to_delete = set()
        for key in self.responses:
            try:
                response, created_at = self.responses[key]
            except __HOLE__:
                continue
            if created_at < created_before:
                keys_to_delete.add(key)

        for key in keys_to_delete:
            self.delete(key)
dataset/ETHPy150Open reclosedev/requests-cache/requests_cache/backends/base.py/BaseCache.remove_old_entries