Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/gmcguire/public_html/concrete5/concrete/vendor/ssddanbrown/htmldiff/tests/HeavyContentTest.php:6 Stack trace: #0 {main} thrown in /home/gmcguire/public_html/concrete5/concrete/vendor/ssddanbrown/htmldiff/tests/HeavyContentTest.php on line 6