def test_get_free_rent_text(self):
     self.assertIsNone(
         DataHelper.get_free_rent_text(
             FreeRentType.objects.get(pk=0),  # 無し
             0,
             0,
             0,
         ), )
     self.assertEqual(
         DataHelper.get_free_rent_text(
             FreeRentType.objects.get(pk=1),  # 月数
             1,
             2000,
             3,
         ),
         '1ヶ月',
     )
     self.assertEqual(
         DataHelper.get_free_rent_text(
             FreeRentType.objects.get(pk=2),  # 期限月
             1,
             2000,
             3,
         ),
         '2000年3月まで',
     )
 def free_rent_text(self):
     return DataHelper.get_free_rent_text(self.free_rent_type,
                                          self.free_rent_months,
                                          self.free_rent_limit_year,
                                          self.free_rent_limit_month)