Как в тесте проверить, что форма принадлежит классу из forms?

...
response = self.authorized_client.get(reverse('posts:post_create'))
        form_fields = {
            'text': forms.fields.CharField,
            'group': forms.fields.ChoiceField,
            'image': forms.fields.ImageField

        }
        for field_name, field_type in form_fields.items():
            with self.subTest(name=field_name, type=field_type):
                form = response.context.get('form')
                self.assertIsNotNone(form)
                self.assertIsInstance(form, PostForm)
...