question: public static byte [ ] digest ( final DigestAlgorithm digestAlgorithm , final DSSDocument document ) throws DSSException { final MessageDigest messageDigest = getMessageDigest ( digestAlgorithm ) ; byte [ ] buffer = new byte [ 1024 ] ; int count = - 1 ; InputStream stream = document . openStream ( ) ; try { while ( ( count = stream . read ( buffer ) ) > 0 ) { messageDigest . update ( buffer , 0 , count ) ; } } catch ( IOException e ) { throw new DSSException ( e ) ; } final byte [ ] digestValue = messageDigest . digest ( ) ; return digestValue ; }
target:  This method allows to digest the data with the given algorithm.