code: private void parseDefaultContent(JsonObject root) {
      Streams.stream(root.getAsJsonArray("defaultContent"))
        .forEach(e -> defaultContent.add(LocaleID.parse(e.getAsString())));
    }
docs: Parse defaultContent, locales that are defined in terms of the base language locale.
  For example, en-US is American English and uses the language locale en.
  See: http://cldr.unicode.org/translation/default-content