createAppLoader example

$adminUiXmlSchemaValidator = new AdminUiXmlSchemaValidator();
        $customEntityEnrichmentService = new CustomEntityEnrichmentService($adminUiXmlSchemaValidator);

        $customEntityXmlSchemaValidator = new CustomEntityXmlSchemaValidator();

        $customEntityLifecycleService = new CustomEntityLifecycleService(
            $customEntityPersister,
            $customEntitySchemaUpdater,
            $customEntityEnrichmentService,
            $customEntityXmlSchemaValidator,
            '',
            $this->createAppLoader(),
        );

        static::assertNull(
            $customEntityLifecycleService->updatePlugin(Uuid::randomHex(), 'not/given')
        );
        static::assertNull(
            $customEntityLifecycleService->updateApp(Uuid::randomHex(), 'not/given')
        );
    }

    public function testUpdatePluginOnlyCustomEntities(): void
    {