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

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

        let sticker_type = sticker_type

            .parse()

            .map_err(|_| RequestParserError::SyntaxError(1, sticker_type.to_owned()))?;

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

        let uri = uri

            .parse()

            .map_err(|_| RequestParserError::SyntaxError(1, uri.to_owned()))?;

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

        let name = name

            .parse()

            .map_err(|_| RequestParserError::SyntaxError(1, name.to_owned()))?;

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

        Ok((Request::StickerGet(sticker_type, uri, name), ""))

    }

    fn parse_response(

        parts: ResponseAttributes<'_>,

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

        let parts: Vec<_> = parts.into();

        let mut parts = parts.into_iter().peekable();

        let (key, sticker) = get_next_property!(parts, Text);

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

        debug_assert!(key == "sticker");

        Ok(sticker.to_string())

    }