//TODO: code review: should the last element be excluded?
final Coupon cp = (Coupon)flow;
if (cp != null) {
if (firstCouponFound) {
assert(nominal == cp.nominal() &&
accrualPeriod == cp.accrualPeriod() &&
//FIXME: implement equals for dayCounters!
dc.getClass() == cp.dayCounter().getClass()):
"cannot aggregate accrued amount of two " +
"different coupons on "+ paymentDate.toString();
} else {