search_api-8.x-1.15/tests/search_api_test_no_ui/src/Plugin/search_api/processor/NoUi.php

<?php

namespace Drupal\search_api_test_no_ui\Plugin\search_api\processor;

use Drupal\search_api\Processor\ProcessorPluginBase;

/**
 * Provides a test processor that should be hidden from the UI.
 *
 * @SearchApiProcessor(
 *   id = "search_api_test_no_ui",
 *   label = @Translation("No UI processor"),
 *   no_ui = true,
 * )
 */
class NoUi extends ProcessorPluginBase {

  /**
   * {@inheritdoc}
   */
  public function supportsStage($stage_identifier) {
    return TRUE;
  }

}