private static List<Pair<String, String>> loadMappings(Region reg) {
    String configUrl = getConfigUrl(reg);
    try {
      List<Pair<String, String>> result = new SmartList<>();
      String json = HttpRequests.request(configUrl).readString();
      for (Map<String, Object> mapping : JsonUtil.<Map<String, Object>>nextList(new JsonReaderEx(json))) {
        if (mapping.size() == 1) {
          Map.Entry<String, Object> entry = mapping.entrySet().iterator().next();
          String pattern = entry.getKey();
          if (!Strings.isEmpty(pattern) && entry.getValue() instanceof String replacement) {
            result.add(Pair.create(pattern, replacement));
          }
        }
      }
      return result;
    }
    catch (Throwable e) {
      LOG.info("Failed to load region-specific url mappings : " + e.getMessage());
    }
    return Collections.emptyList();
  }
private static List<Pair<String, String>> loadMappings(Region reg)