ActionAddForm.php

<?php

namespace Drupal\action;

use Drupal\action\Form\ActionAddForm as ActionAddFormCurrent;
@trigger_error('The ' . __NAMESPACE__ . '\\ActionAddForm is deprecated in Drupal 8.8.0 and will be removed before Drupal 9.0.0. Use ' . __NAMESPACE__ . '\\Form\\ActionAddForm. See https://www.drupal.org/node/3033540', E_USER_DEPRECATED);

/**
 * Provides a form for action add forms.
 *
 * @internal
 *
 * @deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Use
 *   \Drupal\action\Form\ActionEditForm instead.
 *
 * @see https://www.drupal.org/node/3033540
 */
class ActionAddForm extends ActionAddFormCurrent {

}