farm-2.x-dev/modules/core/update/tests/modules/farm_update_test/farm_update_test.module

<?php

/**
 * @file
 * Contains farm_update_test.module.
 */

/**
 * Implements hook_farm_update_exclude_config().
 */
function farm_update_test_farm_update_exclude_config() {
  return ['farm_flag.flag.priority'];
}