public Set<CacheIdentity> getCacheIdentities() {
        // Note: it is possible to have two caches with the same config, e.g. StatisticsDataSourceCacheImpl
        return caches.values()
                .stream()
                .map(cache ->
                        new CacheIdentity(cache.name(), cache.getBasePropertyPath()))
                .collect(Collectors.toSet());
    }
This is only for tests to save providing a {@link Metrics} instance
stroom-cache/stroom-cache-impl/src/main/java/stroom/cache/impl/CacheManagerImpl.java