PluginTestHooks.php

<?php

declare (strict_types=1);
namespace Drupal\plugin_test\Hook;

use Drupal\plugin_test\Plugin\plugin_test\fruit\Apple;
use Drupal\Core\Hook\Attribute\Hook;

/**
 * Hook implementations for plugin_test.
 */
class PluginTestHooks {
    
    /**
     * Implements hook_test_plugin_info().
     */
    public function testPluginInfo() {
        return [
            'apple' => [
                'id' => 'apple',
                'class' => Apple::class,
            ],
        ];
    }
    
    /**
     * Implements hook_plugin_test_alter().
     */
    public function pluginTestAlter(&$definitions) {
        foreach ($definitions as &$definition) {
            $definition['altered'] = TRUE;
        }
        $definitions['user_login']['altered_single'] = TRUE;
    }

}