List<String> getStagedMapNames() {
        return mapDefinitionToUIDMap.keySet()
                .stream()
                .map(MapDefinition::getMapName)
                .collect(Collectors.toList());
    }
@return The map names loaded so far
stroom-pipeline/src/main/java/stroom/pipeline/refdata/store/offheapstore/OffHeapStagingStore.java