Fatal error: Uncaught Error: Interface 'Gloudemans\Shoppingcart\Contracts\InstanceIdentifier' not found in C:\xampp\htdocs\iglooapp\vendor\bumbummen99\shoppingcart\tests\Fixtures\Identifiable.php:7 Stack trace: #0 {main} thrown in C:\xampp\htdocs\iglooapp\vendor\bumbummen99\shoppingcart\tests\Fixtures\Identifiable.php on line 7