code: def is_required(action):
      '''
      _actions possessing the `required` flag and not implicitly optional
      through `nargs` being '*' or '?'
      '''
      return not isinstance(action, _SubParsersAction) and (
      action.required == True and action.nargs not in ['*', '?']f is_required(action):
      '''
      _actions possessing the `required` flag and not implicitly optional
      through `nargs` being '*' or '?'
      '''
      return not isinstance(action, _SubParsersAction) and (
      action.required == True and action.nargs not in ['*', '?'])
docs: _actions possessing the `required` flag and not implicitly optional
      through `nargs` being '*' or '?'