Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in D:\xampp\htdocs\ssw_doc\vendor\myclabs\deep-copy\tests\DeepCopyTest\DeepCopyTest.php:43 Stack trace: #0 {main} thrown in D:\xampp\htdocs\ssw_doc\vendor\myclabs\deep-copy\tests\DeepCopyTest\DeepCopyTest.php on line 43