code: protected String translateFallback(Exception e) {
  
      String messageId = this.name + ":" + this.key;
      LOG.warn("Failed to resolve message (" + messageId + "): " + e.getMessage());
      return translateFallback(messageId);
    }
docs: Called from {@link #translate(Locale)} if localization failed.
  
  @param e is the {@link Exception}.
  @return the fallback message.