if c == nil {
		return nil
	}
	var tmp [binary.MaxVarintLen32]byte
	n := binary.PutUvarint(tmp[:], uint64(c.Type))
	crc := c.Raw
	if len(crc) != c.Type.RawByteLen() {
		return b
	}
	b = append(b, tmp[:n]...)
	b = append(b, crc...)
	if c.Type.Is(ChecksumMultipart) {
		var checksums int
		// Ensure we don't divide by 0: