ErrorServiceTestServiceProvider.php

<?php

namespace Drupal\error_service_test;

use Drupal\Core\DependencyInjection\ContainerBuilder;
use Drupal\Core\DependencyInjection\ServiceModifierInterface;
class ErrorServiceTestServiceProvider implements ServiceModifierInterface {
    
    /**
     * The in-situ container builder.
     *
     * @var \Drupal\Core\DependencyInjection\ContainerBuilder
     */
    public static $containerBuilder;
    
    /**
     * {@inheritdoc}
     */
    public function alter(ContainerBuilder $container) {
        static::$containerBuilder = $container;
    }

}