NTLM auth is failing while processing 2nd challenge response

In NTLMScheme class (NTLMScheme.java), processChallenge function is trying to read challenge using getValue() function.
But it is always returning null.
Challenge is actually stored inside params and can be accessed by getParams() function.
see 150694519-4216bb91-ad43-40d1-ba8e-1818af685560.png