def METHOD_NAME(
        self,
        POST,
        csrf_token,
        admin_attendee,
        duplicate_badge_num_preconditions):
    self._register_group_member_response(
        group_id=duplicate_badge_num_preconditions,
        first_name='Duplicate',
        last_name='Follower',
        legal_name='Duplicate Follower',
        ec_name='Nana Fearless',
        ec_phone='555-555-1234',
        can_spam='1',
        badge_type=str(c.ATTENDEE_BADGE),
        shirt='0',
        zip_code='21211',
        affiliate='',
        requested_depts=['80341158', '224685583'],
        amount_extra='0',
        email='duplicate@example.com',
        found_how='Followed my fearless leader',
        cellphone='555-555-4321',
        staffing='1',
        birthdate='1964-12-30',
        comments='What is even happening?',
        interests=[str(c.ARCADE), str(c.CONSOLE)],
        badge_printed_name='',
        id='None',
        pii_consent='1')
    with Session() as session:
        group = session.query(Group).get(duplicate_badge_num_preconditions)
        badge_nums = [a.badge_num for a in group.attendees]
        # SQLite doesn't support deferred constraints, so our test database
        # doesn't actually have a unique constraint on the badge_num
        # column. So we have to manually check for duplicate badge numbers.
        assert_unique(badge_nums)