code: public static ValidationMessage<Origin> message(
  			LineReader lineReader, Severity severity,
  			String messageKey, Object... params) {
  		return message(lineReader.getCurrentLineNumber(), severity, messageKey, params);
  	}
docs: Creates a validation message.
  
  @param lineReader the flat file line reader.
  @param severity severity of the message
  @param messageKey a key of the message
  @param params parameters of the message
  @return a validation message