Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/agilgo/public_html/demo-chat-ai/vendor/partitech/php-mistral/tests/MessageTest.php:8 Stack trace: #0 {main} thrown in /home/agilgo/public_html/demo-chat-ai/vendor/partitech/php-mistral/tests/MessageTest.php on line 8