Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in C:\MANTUM\xampp2\htdocs\MNT\ventasvariables\libreria\vendor\microsoft\microsoft-graph\tests\Functional\MailTest.php:6 Stack trace: #0 {main} thrown in C:\MANTUM\xampp2\htdocs\MNT\ventasvariables\libreria\vendor\microsoft\microsoft-graph\tests\Functional\MailTest.php on line 6