Burden of proving exception or exemption

In any complaint, information or indictment and in any action or proceeding brought for the enforcement of any provision of NRS 454.181 to 454.530 , inclusive, it is not necessary to negate any exception, excuse, proviso or exemption contained in NRS 454.181 to 454.530 , inclusive, and the burden of proof of any such exception, excuse, proviso or exemption is upon the defendant.