I don't know where/if this is in the docs, but here's what the docstring says in `openstacksdk/openstack/identity/v3/_proxy.py` where it's defined:
```
"""Retrieve a generator of role assignments

        :param kwargs query: Optional query parameters to be sent to limit
            the resources being returned. The options
            are: group_id, role_id, scope_domain_id,
            scope_project_id, inherited_to, user_id, include_names,
            include_subtree.
        :return:
            :class:`~openstack.identity.v3.role_assignment.RoleAssignment`
        """
```
Hope this is helpful!