Method __contains__

python/python3/tornado/options.py:169–171

(self, name: str)

        return (opt.name for opt in self._options.values())

    def __contains__(self, name: str) -> bool:
        name = self._normalize_name(name)
        return name in self._options

    def __getitem__(self, name: str) -> Any:
        return self.__getattr__(name)