'Creates a ZeroCourseGrade and ensures it\'s empty.'

@ddt.data(True, False)
def test_zero(self, assume_zero_enabled):

    with waffle().override(ASSUME_ZERO_GRADE_IF_ABSENT, active=assume_zero_enabled):
        course_data = CourseData(self.request.user, structure=self.course_structure)
        chapter_grades = ZeroCourseGrade(self.request.user, course_data).chapter_grades
        for chapter in chapter_grades:
            for section in chapter_grades[chapter]['sections']:
                for score in section.problem_scores.itervalues():
                    self.assertEqual(score.earned, 0)
                    self.assertEqual(score.first_attempted, None)
                self.assertEqual(section.all_total.earned, 0)
