 
     public func finalData() -> NSData {
         let result = NSMutableData(data: try! handle(engine.finalData()))
-        result.appendData(self.hmac.finalData())
+        result.appendData(hmac.finalData())
         return result
     }
 }

        var result: CCCryptorStatus = CCCryptorStatus(kCCUnimplemented)

        result = CCCryptorUpdate(
            self.cryptor,
            data.bytes, data.length,
            buffer.mutableBytes, outputLength,
            &dataOutMoved)

            iv.bytes,
            &cryptorOut
        )
        cryptor = cryptorOut

        // It is a programming error to create us with illegal values
        // This is an internal class, so we can constrain what is sent to us.
