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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def local_manager_gid(self):
 """Group id of local manager group of current authenticated member. Currently a user can be assigned only to one local manager group. If more than one local manager group is configured, an error is raised. """

        config = self.root['settings']['ugm_localmanager'].attrs
        user = security.authenticated_user(get_current_request())
        if not user:
            return None
        gids = user.group_ids
        adm_gids = list()
        for gid in gids:
            rule = config.get(gid)
            if rule:
                adm_gids.append(gid)
        if len(adm_gids) == 0:
            return None
        if len(adm_gids) > 1:
            msg = (u"Authenticated member defined in local manager "
                   u"groups %s but only one management group allowed for "
                   u"each user. Please contact System Administrator in "
                   u"order to fix this problem.")
            exc = msg % ', '.join(["'%s'" % gid for gid in adm_gids])
            raise Exception(exc)
        return adm_gids[0]