Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\vendor\srmklive\paypal\tests\Feature\AdapterOrdersHelperTest.php:13 Stack trace: #0 {main} thrown in C:\xampp\htdocs\vendor\srmklive\paypal\tests\Feature\AdapterOrdersHelperTest.php on line 13