} else {
challenge = ((AMQP.Connection.Secure) serverResponse).getChallenge();
response = sm.handleChallenge(challenge, this.username, this.password);
}
} catch (ShutdownSignalException e) {
throw new PossibleAuthenticationFailureException(e);
}
} while (connTune == null);
} catch (ShutdownSignalException sse) {
_frameHandler.close();
throw AMQChannel.wrap(sse);