fn parse_request(mut parts: std::str::SplitWhitespace<'_>) -> RequestParserResult<'_> {

        let id = parts.next().ok_or(RequestParserError::UnexpectedEOF)?;

        let id = id

            .parse()

            .map_err(|_| RequestParserError::SyntaxError(0, id.to_string()))?;

        debug_assert!(parts.next().is_none());

        Ok((Request::PlaylistId(id), ""))

    }

    fn parse_response(

        _parts: ResponseAttributes<'_>,

    ) -> Result<Self::Response, ResponseParserError> {

        unimplemented!()