question: public Response onCommand ( POP3Session session , Request request ) { String parameters = request . getArgument ( ) ; if ( session . getHandlerState ( ) == POP3Session . AUTHENTICATION_USERSET && parameters != null ) { return doAuth ( session , session . getUser ( ) , parameters ) ; } else { session . setHandlerState ( POP3Session . AUTHENTICATION_READY ) ; return AUTH_FAILED ; } }
target:  Handler method called upon receipt of a PASS command. Reads in and validates the password.