Here's a minimal example so my comment is not totally vacuous:

```
import unittest
from unittest import mock

class Foo:
    @classmethod
    def bar(cls, baz):
        pass

class TestFoo(unittest.TestCase):
    def test_bar(self):
        with unittest.mock.patch.object(Foo, "bar", autospec=True):
            Foo.bar()
```

->

```
~/› python -m unittest example.py 
E
======================================================================
ERROR: test_bar (example.TestFoo)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "example.py", line 14, in test_bar
    Foo.bar()
TypeError: 'NonCallableMagicMock' object is not callable

----------------------------------------------------------------------
Ran 1 test in 0.001s
```