docs: function _parseMessage(message) {
      try {
        const contentString = message && message.content && message.content.toString();
        return JSON.parse(contentString);
      } catch (err) {
        _emit(TASK_FAILED);
        logger.warn(
          { err, message, options: configWithoutFuncs },
          '[worker#listen] Content is not a valid JSON'
        );
        return null;
      }
    }