def add_arguments(self, parser):
        """Adds the arguments for the firmware command.

        Args:
          self (FirmwareCommand): the ``FirmwareCommand`` instance
          parser (argparse.ArgumentParser): parser to add the commands to

        Returns:
          ``None``
        """
        group = parser.add_mutually_exclusive_group(required=True)
        group.add_argument('-d', '--downgrade', action='store_true',
                           help='downgrade the J-Link firmware')
        group.add_argument('-u', '--upgrade', action='store_true',
                           help='upgrade the J-Link firmware')
        return self.add_common_arguments(parser, False)
Adds the arguments for the firmware command.

        Args:
          self (FirmwareCommand): the ``FirmwareCommand`` instance
          parser (argparse.ArgumentParser): parser to add the commands to

        Returns:
          ``None``