Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/peverde/public_html/vendor/symfony/serializer/Tests/Mapping/Loader/XmlFileLoaderTest.php:22 Stack trace: #0 {main} thrown in /home/peverde/public_html/vendor/symfony/serializer/Tests/Mapping/Loader/XmlFileLoaderTest.php on line 22