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

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

        let prio = prio

            .parse()

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

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

        let songids = songids

            .split(',')

            .map(|s| {

                s.parse()

                    .map_err(|_| RequestParserError::SyntaxError(0, s.to_string()))

            })

            .collect::<Result<Vec<u32>, RequestParserError>>()?;

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

        Ok((Request::PrioId(prio, songids), ""))

    }

    fn parse_response(

        parts: ResponseAttributes<'_>,

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

        debug_assert!(parts.is_empty());

        Ok(())

    }