Wrap a message with a sequence number and encrypt it.

        Args:
            mesg: The mesg to encrypt.

        Returns:
            bytes: The encrypted message.

def encrypt(self, mesg):
        '''
        Wrap a message with a sequence number and encrypt it.

        Args:
            mesg: The mesg to encrypt.

        Returns:
            bytes: The encrypted message.
        '''
        seqn = next(self._tx_sn)
        rv = self._tx_tinh.enc(s_msgpack.en((seqn, mesg)))
        return rv