def assert_month(self, start_month, actual_end_month):
        if start_month == 1:
            expected_end_month = 12
        else:
            expected_end_month = 1 - start_month

        self.assertEqual(expected_end_month, actual_end_month)
dataset/ETHPy150Open quantopian/zipline/tests/risk/test_risk_period.py/TestRisk.assert_month/swapped operands of `-`