apollo-configservice/src/main/java/com/ctrip/framework/apollo/configservice/controller/ConfigController.java/ConfigController/mergeReleaseConfigurations
class ConfigController:  Map<String, String> mergeReleaseConfigurations(List<Release> releases) {
    Map<String, String> result = Maps.newLinkedHashMap();
    for (Release release : Lists.reverse(releases)) {
      result.putAll(gson.fromJson(release.getConfigurations(), configurationTypeReference));
    }
    return result;
  }