question: public synchronized String generateCallIdentifier ( String address ) { String date = Long . toString ( System . currentTimeMillis ( ) + callIDCounter ++ + rand . nextLong ( ) ) ; byte cid [ ] = digester . digest ( date . getBytes ( ) ) ; String cidString = Utils . toHexString ( cid ) ; return cidString + "@" + address ; }
target:  Generate a call identifier. This is useful when we want to generate a call identifier in advance of generating a message.