def METHOD_NAME(project: str, action: str,
                          version: common.VersionKey) -> RollbackStep:
    """Creates a rollback step that starts or stops an AppEngine version.
    Args:
        project: The GCP project of the AppEngine application.
        action: Start or Stop.
        version: The version being managed.
    """
    return RollbackStep(
        f'{action.title()} {version.version_id} in {version.service_id}',
        ('gcloud', 'app', 'versions', action, version.version_id, '--quiet',
         '--service', version.service_id, '--project', project))