In any action brought under or arising out of any of the provisions of this chapter, or of any ordinance imposing a license tax, the fact that a party thereto represented himself as engaged in any business or calling for the transaction of which a license is required, or that such party exhibited a sign indicating such business or calling, shall be conclusive evidence of the liability of such party to pay for a license for such business. (Ord. No. 1078, § 7.35.)