What constitutes certainty as to sum in negotiable instruments

Sec. 2. What constitutes certainty as to sum. - The sum payable is a sum certain within the meaning of this Act, although it is to be paid (a) with interest; or (b) by stated installments; or (c) by stated installments, with a provision that, upon default in payment of any installment or of interest, the whole shall become due; or (d) with exchange, whether at a fixed rate or at the current rate; or (e) with costs of collection or an attorney's fee, in case payment shall not be made at maturity.