def command(self, *args, **kwargs):
        """A shortcut decorator for declaring and attaching a command to
        the group.  This takes the same arguments as :func:`command` but
        immediately registers the created command with this instance by
        calling into :meth:`add_command`.
        """
        def decorator(f):
            cmd = command(*args, **kwargs)(f)
            self.add_command(cmd)
            return cmd
        return decorator