@Override
    public void purge(final long refStreamId, final long partIndex) {
        // Purge sequentially
        final RefDataOffHeapStore effectiveStore = getEffectiveStore(refStreamId);
        LOGGER.debug("Calling purge() - refStreamId {}, partIndex: {}, store: {}",
                refStreamId, partIndex, effectiveStore);
        effectiveStore.purge(refStreamId, partIndex);
        checkLegacyStoreState();
    }
Get all ref stores keyed by feed name

@return Map of feedName => {@link RefDataOffHeapStore}
stroom-pipeline/src/main/java/stroom/pipeline/refdata/store/offheapstore/DelegatingRefDataOffHeapStore.java