public boolean isRefStreamAvailable(final RefStreamDefinition refStreamDefinition) {
        return availableRefStreamDefinitions.contains(refStreamDefinition);
    }
A pipeline scoped holder for a {@link RefDataLoader} and a place to store transient state relating to
the loading of reference data using a reference data pipeline.
stroom-pipeline/src/main/java/stroom/pipeline/refdata/RefDataLoaderHolder.java