code: public Set<String> GetResourceLocales(boolean exclude_system,
        boolean merge_equivalent_languages) {
      ATRACE_CALL();
      Set<String> locales = new HashSet<>();
      for (final PackageGroup package_group : package_groups_) {
        for (final ConfiguredPackage package_ : package_group.packages_) {
          if (exclude_system && package_.loaded_package_.IsSystem()) {
            continue;
          }
          package_.loaded_package_.CollectLocales(merge_equivalent_languages, locales);
        }
      }
      return locales;
    }
docs: boolean merge_equivalent_languages = false);