def METHOD_NAME(
        appengine_admin: appengine.AppEngineAdmin,
        version: common.VersionKey,
        started_before: datetime.datetime
) -> Tuple[steps.KillNomulusInstance, ...]:
    # yapf: enable
    instances = appengine_admin.list_instances(version)
    return tuple([
        steps.kill_nomulus_instance(appengine_admin.project, version,
                                    inst.instance_name) for inst in instances
        if inst.start_time <= started_before
    ])