Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/stagingaicapital/public_html/app/Vendor/microsoft/kiota-serialization-multipart/tests/MultipartSerializationWriterTest.php:20 Stack trace: #0 {main} thrown in /home/stagingaicapital/public_html/app/Vendor/microsoft/kiota-serialization-multipart/tests/MultipartSerializationWriterTest.php on line 20