code: def get_driver(self, namespace, parsed_args, **kwargs):
          
          option, dest = self._namespace_to_option(namespace)
          dest_prefix = '{0}_'.format(dest)
          driver_name = getattr(parsed_args, dest, 'default')
          driver_extension = self.driver_managers[namespace][driver_name]
          return driver_extension.plugin.from_args(
              parsed_args, dest_prefix, **kwargs)
docs: Get mutually-exlusive plugin for plugin namespace.