in client/src/main/scala/com/gu/anghammarad/AWS.scala [38:45]
private[anghammarad] def asScala[T](cf: CompletableFuture[T]): Future[T] = {
val p = Promise[T]()
cf.whenCompleteAsync{ (result, ex) =>
if (result == null) p failure ex
else p success result
}
p.future
}