def __missing__(self, key):
        if self.default_factory is None:
            raise KeyError(key)
        else:
            ret = self[key] = self.default_factory(name=key)
            return ret
def lazy_ngettext(self, singular: str, plural: str, lang: str = None, n=1):
        if not babel_imported:
            raise RuntimeError('babel module is not imported. Check that you installed it.')
        return LazyProxy(self.ngettext, singular, plural, lang, n, enable_cache=False)