'With showanswer="correct_or_past_due" should show answer after the answer is correct
or after the problem is closed for everyone--e.g. after due date + grace period.'

def test_showanswer_correct_or_past_due(self):

    answer_correct = CapaFactory.create(showanswer='correct_or_past_due', max_attempts='1', attempts='0', due=self.tomorrow_str, correct=True)
    self.assertTrue(answer_correct.answer_available())
    past_due_date = CapaFactory.create(showanswer='correct_or_past_due', max_attempts='1', attempts='0', due=self.yesterday_str)
    self.assertTrue(past_due_date.answer_available())
    past_due_date_correct = CapaFactory.create(showanswer='correct_or_past_due', max_attempts='1', attempts='0', due=self.yesterday_str, correct=True)
    self.assertTrue(past_due_date_correct.answer_available())
    still_in_grace = CapaFactory.create(showanswer='correct_or_past_due', max_attempts='1', attempts='1', due=self.yesterday_str, graceperiod=self.two_day_delta_str)
    self.assertFalse(still_in_grace.answer_available())
