private String feedNameToSubDirName(final String feedName) {
        Objects.requireNonNull(feedName);
        final String cleanedFeedName = FEED_NAME_CLEAN_PATTERN.matcher(feedName.toUpperCase())
                .replaceAll(FEED_NAME_CLEAN_REPLACEMENT);

        final List<DocRef> feedDocRefs = feedStore.findByName(feedName);
        if (feedDocRefs.isEmpty()) {
            throw new RuntimeException(LogUtil.message("Expecting to find feed doc for name " + feedName));
        } else if (feedDocRefs.size() > 1) {
            throw new RuntimeException(LogUtil.message("Found " + feedDocRefs.size() + " feed docs for name "
                                                       + feedName + ". Feed names should be unique."));
        }
        final String feedDocUuid = feedDocRefs.getFirst().getUuid();

        // It is possible for two feed names to share the same cleaned name, so add a UUID on the end to make it
        // is involved, so it may tie up the fork join pool
        final String subDirName = String.join(DELIMITER, cleanedFeedName, feedDocUuid);
        LOGGER.debug("Using subDirName: '{}' for feedName: '{}', ", feedName, subDirName);
        return subDirName;
    }
@return The count of feed stores initialised, 1 or 0.
stroom-pipeline/src/main/java/stroom/pipeline/refdata/store/offheapstore/DelegatingRefDataOffHeapStore.java