def test_invalid_axis_type_in_tuple(self):
     with self.assertRaises(TypeError):
         functions.Sum((1, 'x'))
 def test_duplicate_axis(self):
     with self.assertRaises(ValueError):
         functions.Sum((0, 0))
 def test_invalid_axis_type(self):
     with self.assertRaises(TypeError):
         functions.Sum([0])