def _get_item_url(  # noqa: WPS234
        self,
        identifier: str,
        fallback: Optional[Callable[[str], Sequence[str]]] = None,
    ) -> str:
        try:
            return self._url_map[identifier]
        except KeyError:
            if fallback:
                new_identifiers = fallback(identifier)
                for new_identifier in new_identifiers:
                    with contextlib.suppress(KeyError):
                        url = self._get_item_url(new_identifier)
                        self._url_map[identifier] = url
                        return url
            raise

    def get_item_url(  # noqa: WPS234
        self,
        identifier: str,
        from_url: Optional[str] = None,
        fallback: Optional[Callable[[str], Sequence[str]]] = None,
    ) -> str:
        try:
            url = self._get_item_url(identifier, fallback)
        except KeyError:
            if identifier in self._abs_url_map:
                return self._abs_url_map[identifier]
            raise
        if from_url is not None:
            return relative_url(from_url, url)
        return url