public List<UniqueId> getContainedReceiptIds() {
            return dataFeedRequestItems.stream()
                    .filter(item ->
                            item.type().equals(StroomZipFileType.META.getExtension()))
                    .map(DataFeedRequestItem::getContentAsAttributeMap)
                    .map(attributeMap ->
                            attributeMap.get(StandardHeaderArguments.RECEIPT_ID))
                    .map(UniqueId::parse)
                    .toList();
        }
The {@link UniqueId} of the wrapping zip
stroom-proxy/stroom-proxy-app/src/test/java/stroom/proxy/app/MockHttpDestination.java