Fatal error: Uncaught Error: Class "Tests\TestCase" not found in C:\xampp\htdocs\smsgateway2\tests\Unit\Infrastructure\Smpp\Php8SmppClientAdapterTest.php:25 Stack trace: #0 {main} thrown in C:\xampp\htdocs\smsgateway2\tests\Unit\Infrastructure\Smpp\Php8SmppClientAdapterTest.php on line 25