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

        let playlist_name = parts

            .next()

            .ok_or(RequestParserError::UnexpectedEOF)?

            .to_string();

        let mut from = None;

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

        let to = parts.next();

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

        let to = if let Some(to) = to {

            from = Some(from_or_range_or_to.parse().map_err(|_| {

                RequestParserError::SyntaxError(0, from_or_range_or_to.to_string())

            })?);

            to.parse()

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

            from_or_range_or_to

                .parse()

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

        Ok((Request::PlaylistMove(playlist_name, from, to), ""))

    }

    fn parse_response(

        parts: ResponseAttributes<'_>,

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

        debug_assert!(parts.is_empty());

        Ok(())

    }