in src/main/scala/InvoiceHelper.scala [84:90]
def processAdjustments(accountId: String, adjustments: List[InvoiceItemAdjustment]): String \/ List[CreateInvoiceItemAdjustmentResult] = {
logInfo(accountId, s"processing adjustments")
val adjustmentAttempts = adjustments.map { adjustment => createInvoiceItemAdjustment(accountId, adjustment) }
val failures = adjustmentAttempts.collect { case -\/(error) => error }
val successes = adjustmentAttempts.collect { case \/-(adjustmentResult) => adjustmentResult }
if (failures.isEmpty) successes.right else failures.toString.left
}