Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\astra-backoffice\vendor\tijsverkoyen\css-to-inline-styles\tests\Css\Rule\ProcessorTest.php:9 Stack trace: #0 {main} thrown in C:\xampp\htdocs\astra-backoffice\vendor\tijsverkoyen\css-to-inline-styles\tests\Css\Rule\ProcessorTest.php on line 9