@Override
    public String getAuthorizationID() {
        if (completed) {
            return authzid;
        } else {
            throw new IllegalStateException("PLAIN authentication not completed");
        }
    }
Reports the authorization ID in effect for the client of this
session.
This method can only be called if isComplete() returns true.
@return The authorization ID of the client.
@exception IllegalStateException if this authentication session has not completed
xmppserver/src/main/java/org/jivesoftware/openfire/sasl/SaslServerPlainImpl.java