in lambda/src/main/scala/pricemigrationengine/model/AmendmentData.scala [149:154]
def individualChargeAmount(ratePlanCharge: ZuoraRatePlanCharge): Either[Double, BigDecimal] =
ratePlanCharge.price match {
case None => ratePlanCharge.discountPercentage.toLeft(0)
case Some(p) if p > 0 => Right(p)
case Some(_) => Right(0)
}