E.g. for the `CreateMixin` the `.create(...)` method returns things like [`ProjectMergeRequest`](https://github.com/python-gitlab/python-gitlab/blob/181390a4e07e3c62b86ade11d9815d36440f5817/gitlab/v4/objects/merge_requests.py#L143) but not the `base.RESTObject` as specified [here](https://github.com/python-gitlab/python-gitlab/blob/181390a4e07e3c62b86ade11d9815d36440f5817/gitlab/mixins.py#L274). --- `python-gitlab` version: 3.5.0