Fatal error: Uncaught Error: Class "MediaWikiLangTestCase" not found in C:\xampp\htdocs\extensions\TemplateStyles\tests\phpunit\TemplateStylesContentHandlerTest.php:16 Stack trace: #0 {main} thrown in C:\xampp\htdocs\extensions\TemplateStyles\tests\phpunit\TemplateStylesContentHandlerTest.php on line 16