docs: function bundleError(res, statusCode, error, params) {
      var message = "Mendel: ";
      if (!error) {
          message += (statusCode === 404 ? 'Bundle not found' : 'Unable to create Bundle');
      } else {
          message += error.code + ' - ' + error.message;
      }
  
      debug([(error ? error.code : 'UNKNOWN'), 'hash=' + params.hash, 'bundle=' + params.bundle].join(' '));
  
      res.status(statusCode).send(message);
  }