Fatal error: Uncaught Error: Class "Tests\TestCase" not found in C:\xampp\htdocs\gnu_7\g7\tests\Feature\Api\Admin\PluginInstallWithVendorModeTest.php:15 Stack trace: #0 {main} thrown in C:\xampp\htdocs\gnu_7\g7\tests\Feature\Api\Admin\PluginInstallWithVendorModeTest.php on line 15