def test_calculate_returns_C(self): self.assertEqual('C', grader.calculate(75))
def test_calculate_returns_None(self): self.assertEqual('F', grader.calculate(5))
def test_calculate_returns_A(self): self.assertEqual('A', grader.calculate(95))
def test_calculate_returns_B(self): self.assertEqual('B', grader.calculate(90))
def test_calculate_grade_B(self): self.assertEqual('B', grader.calculate(85))
def test_calculate_grade_D(self): self.assertEqual('D', grader.calculate(65))
def test_calculate_grade_c(self): self.assertEqual('c', grader.calculate(75))