code: public String localize(PrefixKind pk, String key, Object... args) {
          if (useRawMessages)
              return pk.key(key);
          else
              return messages.getLocalizedString(pk.key(key), args);
      }
docs: Find a localized string in the resource bundle.
  @param key    The key for the localized string.
  @param args   Fields to substitute into the string.