Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/esecureh/public_html/magdemo/vendor/magento/module-downloadable/Test/Unit/Helper/Catalog/Product/ConfigurationTest.php:26 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/vendor/magento/module-downloadable/Test/Unit/Helper/Catalog/Product/ConfigurationTest.php on line 26