Fatal error: Uncaught Error: Class "Tests\TestCase" not found in C:\xampp\htdocs\smsgateway\tests\Feature\Smpp\LifecycleMigrationCompatibilityIntegrationTest.php:14 Stack trace: #0 {main} thrown in C:\xampp\htdocs\smsgateway\tests\Feature\Smpp\LifecycleMigrationCompatibilityIntegrationTest.php on line 14