code: public Warning createWarning(final String fileName, final int start, final String category, final String message) {
          return new Warning(fileName, start, getGroup(), category, message);
      }
docs: Creates a new instance of {@link Warning} using the parser's group as
  warning type.
  
  @param fileName
  the name of the file
  @param start
  the first line of the line range
  @param category
  the warning category
  @param message
  the message of the warning
  @return the warning