question: private byte [ ] writeCheckedBytes ( MessageNano proto ) { CheckedMessage wrapper = new CheckedMessage ( ) ; wrapper . payload = MessageNano . toByteArray ( proto ) ; CRC32 checksum = new CRC32 ( ) ; checksum . update ( wrapper . payload ) ; wrapper . checksum = checksum . getValue ( ) ; return MessageNano . toByteArray ( wrapper ) ; }
target:  Wrap a proto in a CheckedMessage and compute the checksum. 