def rotation_matrix(self):
        return self._parent_orient
ensures error raised on bad default instance type
dataset/ETHPy150Open sympy/sympy/sympy/vector/orienters.py/Orienter.rotation_matrix--crossover with--dataset/ETHPy150Open nii-cloud/dodai-compute/nova/tests/test_instance_types.py/InstanceTypeTestCase.test_will_not_get_bad_default_instance_type