Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /opt/lampp/htdocs/myhospitalnow/mhn-hospital-ms/vendorback/theseer/tokenizer/tests/XMLSerializerTest.php:9 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/myhospitalnow/mhn-hospital-ms/vendorback/theseer/tokenizer/tests/XMLSerializerTest.php on line 9