Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp8\htdocs\Gsheet\vendor\psr\log\Psr\Log\Test\LoggerInterfaceTest.php:15 Stack trace: #0 {main} thrown in C:\xampp8\htdocs\Gsheet\vendor\psr\log\Psr\Log\Test\LoggerInterfaceTest.php on line 15