Fatal error: Uncaught Error: Class "MediaWikiUnitTestCase" not found in /var/www/html/extensions/Math/tests/phpunit/unit/WikiTexVC/Mhchem/MMLmhchemTest.php:23 Stack trace: #0 {main} thrown in /var/www/html/extensions/Math/tests/phpunit/unit/WikiTexVC/Mhchem/MMLmhchemTest.php on line 23