@Override
    public boolean isComplete() {
        return state == State.COMPLETE;
    }
Determines whether the authentication exchange has completed.
This method is typically called after each invocation of
{@code evaluateResponse()} to determine whether the
authentication has completed successfully or should be continued.
@return true if the authentication exchange has completed; false otherwise.
xmppserver/src/main/java/org/jivesoftware/openfire/sasl/ScramSha1SaslServer.java