Fatal error: Uncaught Error: Class 'PHPUnit_Framework_TestCase' not found in /var/www/html/a2billing/vendor/sebastian/diff/tests/LCS/TimeEfficientImplementationTest.php:18 Stack trace: #0 {main} thrown in /var/www/html/a2billing/vendor/sebastian/diff/tests/LCS/TimeEfficientImplementationTest.php on line 18