docs: def exit(self, status=EXIT_OK, message=None):
          """
          Terminate the script.
          """
          if not self.parser:
              self.parser = argparse.ArgumentParser()
          if self.msg_on_error_only:
              # if msg_on_error_only is True
              if status != EXIT_OK:
                  # if we have an error we'll exit with the message also.
                  self.parser.exit(status, message)
              else:
                  # else we'll exit with the status ongly
                  self.parser.exit(status, None)
          else:
              # else if msg_on_error_only is not True
              # we'll exit with the status and the message
              self.parser.exit(status, message)