code: private void fillConfMap(Map<PropertyKey, Map<Optional<String>, List<String>>> targetMap,
        Map<Address, List<ConfigRecord>> recordMap) {
      for (Map.Entry<Address, List<ConfigRecord>> record : recordMap.entrySet()) {
        Address address = record.getKey();
        String addressStr = String.format("%s:%s", address.getHost(), address.getRpcPort());
        for (ConfigRecord conf : record.getValue()) {
          PropertyKey key = conf.getKey();
          if (key.getConsistencyLevel() == ConsistencyCheckLevel.IGNORE) {
            continue;
          }
          Optional<String> value = conf.getValue();
          targetMap.putIfAbsent(key, new HashMap<>());
          Map<Optional<String>, List<String>> values = targetMap.get(key);
          values.putIfAbsent(value, new ArrayList<>());
          values.get(value).add(addressStr);
        }
      }
    }
docs: Fills the configuration map.
  
  @param targetMap the map to fill
  @param recordMap the map to get data from