'Post process assignment list for domain roles.
Domain roles are only designed to do the job of inferring other roles
and since that has been done before this method is called, we need to
remove any assignments that include a domain role.'

def _strip_domain_roles(self, role_refs):

    def _role_is_global(role_id):
        ref = self.role_api.get_role(role_id)
        return (ref['domain_id'] is None)
    filter_results = []
    for ref in role_refs:
        if _role_is_global(ref['role_id']):
            filter_results.append(ref)
    return filter_results
