Sort the subcommands alphabetically

def _iter_indented_subactions(self, action):
        """
        Sort the subcommands alphabetically
        """
        try:
            get_subactions = action._get_subactions
        except AttributeError:
            pass
        else:
            self._indent()
            if isinstance(action, argparse._SubParsersAction):
                for subaction in sorted(
                        get_subactions(), key=lambda x: x.dest):
                    yield subaction
            else:
                for subaction in get_subactions():
                    yield subaction
            self._dedent()