code: function getExtraFields (cartoError) {
    var errorlist = _getErrorList(cartoError);
    var listedError = _getListedError(cartoError, errorlist);
  
    return {
      friendlyMessage: listedError.friendlyMessage,
      errorCode: listedError.errorCode
    };
  }
docs: Returns two parameters to enrich a CartoError.
  - friendlyMessage: A easy to understand error description.
  - errorCode: Am unique error code
  
  @param {CartoError} cartoError
  
  @returns {object} - An object containing a friendly message and a errorCode