fn unescape(buf: &[u8]) -> Result<Vec<u8>> {
    let mut res = Vec::with_capacity(512);
    let mut bytes = buf.bytes();
    while let Some(Ok(byte)) = bytes.next() {
        if byte == 0xFF { // Got an escape code?
            match bytes.next() { // Add the appropriate byte based on the following byte.
                Some(Ok(0xFF)) => res.push(0xFF),
                Some(Ok(0xFE)) => res.push(0x00),
                Some(Ok(0xFD)) => res.push(0x0A),
                Some(Ok(0xFC)) => res.push(0x0D),
                Some(Ok(b)) => bail!("Invalid escape sequence: 0xFF 0x{b:X}"),
                _ => bail!("Escaped data truncated.")
            }
        } else {
            res.push(byte)
        }
    }
    Ok(res)
}