def METHOD_NAME(self, identifier: str) -> Optional[str]:
    """
    Inputs:
        identifer: unique folder identifier from Google Drive URL
    if identifier is in the config file, then return the name assigned to the identifier
    otherwise return None
    """
    ini_file = self.config_file()
    if ini_file is None:
        return None
    config = configparser.ConfigParser()
    config.read(ini_file)
    for name in config.sections():
        props = config[name]
        if "type" in props and props["type"] == "drive":
            if "root_folder_id" in props and props["root_folder_id"] == identifier:
                return name
    return None