def on_cleanup_error(function, path, excinfo):
                click.secho("warning: failed to remove file or directory: {}\n"
                            "please delete it manually.".format(path),
                            fg="red")
def __getitem__(self, key):
        logger.debug("Get /%s config key", "/".join(self._path + (key,)))
        value = self._collection[key]
        return self._to_python(value)