Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\milegajo\vendor\sabberworm\php-css-parser\tests\RuleSet\DeclarationBlockTest.php:15 Stack trace: #0 {main} thrown in C:\xampp\htdocs\milegajo\vendor\sabberworm\php-css-parser\tests\RuleSet\DeclarationBlockTest.php on line 15