def _precache(self):
        """Cache and process predefined auto-references."""
        for conf, options in self._predefined_refs.items():
            if conf is self._processed:
                processed = dict((option, functor())
                                 for option, functor in options.items())
                self._cached[conf] = processed
                self._processed[conf] = processed
dataset/ETHPy150Open openstack/anvil/anvil/cfg.py/YamlRefLoader._precache/operator `not in` -> `is`