'Check an assignment/grant role id.
:raises keystone.exception.RoleAssignmentNotFound: If the role
assignment doesn\'t exist.
:returns: None or raises an exception if grant not found'

@abc.abstractmethod
def check_grant_role_id(self, role_id, user_id=None, group_id=None, domain_id=None, project_id=None, inherited_to_projects=False):

    raise exception.NotImplemented()
