SettingsTrayFormAnnotationIsClassBlock.php

<?php

namespace Drupal\settings_tray_test\Plugin\Block;

use Drupal\Core\Block\Attribute\Block;
use Drupal\Core\Block\BlockBase;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\settings_tray_test\Form\SettingsTrayFormAnnotationIsClassBlockForm;

/**
 * Block that explicitly provides a "settings_tray" form class.
 */
class SettingsTrayFormAnnotationIsClassBlock extends BlockBase {
    
    /**
     * {@inheritdoc}
     */
    public function build() {
        return [
            '#markup' => '<span>class</span>',
        ];
    }

}