'Construct Namedtuple Challenges
:param str domain: domain of the enrollee
:param list path: List of indices from `challenges`.
:returns: achalls, list of challenge type
:class:`certbot.achallenges.Indexed`
:rtype: list
:raises .errors.Error: if challenge type is not recognized'

def _challenge_factory(self, domain, path):

    achalls = []
    for index in path:
        challb = self.authzr[domain].body.challenges[index]
        achalls.append(challb_to_achall(challb, self.account.key, domain))
    return achalls
