class BatchUserAction

class BatchUserAction extends ActionBase {
    
    /**
     * {@inheritdoc}
     */
    public function executeMultiple(array $entities) {
        $operations = [];
        foreach ($entities as $entity) {
            $operations[] = [
                [
                    static::class,
                    'processBatch',
                ],
                [
                    [
                        'entity_type' => $entity->getEntityTypeId(),
                        'entity_id' => $entity->id(),
                    ],
                ],
            ];
        }
        if ($operations) {
            $batch = [
                'operations' => $operations,
                'finished' => [
                    static::class,
                    'finishBatch',
                ],
            ];
            batch_set($batch);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function execute($entity = NULL) {
        assert($entity instanceof ContentEntityInterface);
        $this->executeMultiple([
            $entity,
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function access($object, ?AccountInterface $account = NULL, $return_as_object = FALSE) {
        return TRUE;
    }
    
    /**
     * Processes the batch item.
     *
     * @param array $data
     *   Keyed array of data to process.
     * @param array $context
     *   The batch context.
     */
    public static function processBatch($data, &$context) {
        if (!isset($context['results']['processed'])) {
            $context['results']['processed'] = 0;
            $context['results']['theme'] = \Drupal::service('theme.manager')->getActiveTheme(\Drupal::routeMatch())
                ->getName();
        }
        $context['results']['processed']++;
    }
    
    /**
     * Finish batch.
     *
     * @param bool $success
     *   Indicates whether the batch process was successful.
     * @param array $results
     *   Results information passed from the processing callback.
     */
    public static function finishBatch($success, $results) {
        \Drupal::messenger()->addMessage(\Drupal::translation()->formatPlural($results['processed'], 'One item has been processed.', '@count items have been processed.'));
        \Drupal::messenger()->addMessage($results['theme'] . ' theme used');
    }

}