'The actual test'

@patch('xmodule.tabs.CourseTab.from_json', side_effect=mock_tab_from_json)
def test_inheritance(self, _from_json):

    locator = BlockUsageLocator(CourseLocator(org='testx', course='GreekHero', run='run', branch=BRANCH_NAME_DRAFT), 'problem', 'problem3_2')
    node = modulestore().get_item(locator)
    self.assertEqual(node.graceperiod, datetime.timedelta(hours=2))
    locator = BlockUsageLocator(CourseLocator(org='testx', course='GreekHero', run='run', branch=BRANCH_NAME_DRAFT), 'problem', 'problem1')
    node = modulestore().get_item(locator)
    self.assertEqual(node.graceperiod, datetime.timedelta(hours=4))
