Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\r10csm\vendor\egulias\email-validator\tests\EmailValidator\Validation\MessageIDValidationTest.php:9 Stack trace: #0 {main} thrown in C:\xampp\htdocs\r10csm\vendor\egulias\email-validator\tests\EmailValidator\Validation\MessageIDValidationTest.php on line 9