Thanks for the great library. Unfortunatelly, I can't find a way to set multiple assignees to merge request. GitLab API supports this feature via assignee_ids field, but it seems that gitlab.v4.objects.MergeRequest object lacks this field. Could you please add the support for this feature (or, maybe, I just missed it somehow?).

PS: For now I fixed this with a quick hack:

attrs = (self._gitlab._objects.ProjectMergeRequestManager._update_attrs[1] + tuple(["assignee_ids"]))
self._gitlab._objects.ProjectMergeRequestManager._update_attrs = ((), attrs)

where self._gitlab is an instance of gitlab.Gitlab. Looks like it works :)