Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/html/includes/release/pdfmerger-050/vendor/tomsgu/pdf-merger/tests/Unit/PdfFileTest.php:16 Stack trace: #0 {main} thrown in /var/www/html/includes/release/pdfmerger-050/vendor/tomsgu/pdf-merger/tests/Unit/PdfFileTest.php on line 16