public RefStreamPurgeCounts add(final RefStreamPurgeCounts other) {
            return increment(
                    other.mapsDeletedCount,
                    other.valuesDeletedCount,
                    other.valuesDeReferencedCount
            );
        }
For use in testing at SMALL scale. Dumps the content of each DB to the logger.
stroom-pipeline/src/main/java/stroom/pipeline/refdata/store/offheapstore/RefDataOffHeapStore.java