in src/main/scala/com/gu/invoicing/nextinvoicedate/Impl.scala [39:49]
def collectRelevantInvoiceItems(
subscriptionName: String,
invoiceItems: List[InvoiceItem],
): List[InvoiceItem] = {
invoiceItems.iterator
.filter(_.subscriptionName == subscriptionName)
.filterNot(_.productName == "Discounts")
.filterNot(_.chargeAmount < 0.0)
.filterNot(v => v.serviceStartDate == v.serviceEndDate)
.toList
}