Implements hook_system_theme_info().
function update_test_system_theme_info() {
$themes['update_test_basetheme'] = drupal_get_path('module', 'update') . '/tests/themes/update_test_basetheme/update_test_basetheme.info.yml';
$themes['update_test_subtheme'] = drupal_get_path('module', 'update') . '/tests/themes/update_test_subtheme/update_test_subtheme.info.yml';
return $themes;
}