code: private Map<PropertyKey, Map<Optional<String>, List<String>>> generateConfMap() {
      Map<PropertyKey, Map<Optional<String>, List<String>>> confMap = new HashMap<>();
      fillConfMap(confMap, mMasterStore.getConfMap());
      fillConfMap(confMap, mWorkerStore.getConfMap());
      return confMap;
    }
docs: Generates the configuration map to find wrong configuration.
  The map is of format Map<PropertyKey, Map<Value, List<Host:Port>>.
  
  @return the generated configuration map