def parse_args(self, args=None, namespace=None):
        """
        Wrapper for :meth:`argparse.ArgumentParser.parse_args`.  If `namespace`
        is not defined, :class:`argh.dispatching.ArghNamespace` is used.
        This is required for functions to be properly used as commands.
        """
        namespace = namespace or ArghNamespace()
        return super(ArghParser, self).parse_args(args, namespace)