Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /opt/lampp/htdocs/us/vendor/neutron/temporary-filesystem/tests/Neutron/TemporaryFilesystem/Tests/ManagerTest.php:8 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/us/vendor/neutron/temporary-filesystem/tests/Neutron/TemporaryFilesystem/Tests/ManagerTest.php on line 8