EntityFormModeListBuilder.php

<?php

namespace Drupal\field_ui;


/**
 * Defines a class to build a listing of form mode entities.
 *
 * @see \Drupal\Core\Entity\Entity\EntityFormMode
 */
class EntityFormModeListBuilder extends EntityDisplayModeListBuilder {
    
    /**
     * Filters entities based on their form mode handlers.
     *
     * @param $entity_type
     *   The entity type of the entity that needs to be validated.
     *
     * @return bool
     *   TRUE if the entity has any forms, FALSE otherwise.
     */
    protected function isValidEntity($entity_type) {
        return $this->entityTypes[$entity_type]
            ->hasFormClasses();
    }

}