How to catch authentication error with SNMP4j sendtrap

Question

With SNMP4j send trap I am not able to catch the Authentication Failure.

With SNMP4j send trap I am not able to catch the Authentication Failure when I use Snmp.send(pdu, uTarget); I get a null response if i give wrong password. I tried even using Snmp.getMessageDispatcher()).addAuthenticationFailureListener(....) Anyone who has achieved catching auth errors please inform. Thanks.