Fatal error: Uncaught Error: Class 'PHPUnit_Framework_TestCase' not found in /var/www/sites/for_new_app/Chat-API-master/src/libaxolotl-php/tests/util/test_byteutil.php:5 Stack trace: #0 {main} thrown in /var/www/sites/for_new_app/Chat-API-master/src/libaxolotl-php/tests/util/test_byteutil.php on line 5