Fatal error: Uncaught Error: Interface 'Magento\Framework\Event\ObserverInterface' not found in /home/esecureh/public_html/magdemo/dev/tests/integration/_files/Magento/TestModuleQuoteTotalsObserver/Observer/AfterCollectTotals.php:13 Stack trace: #0 {main} thrown in /home/esecureh/public_html/magdemo/dev/tests/integration/_files/Magento/TestModuleQuoteTotalsObserver/Observer/AfterCollectTotals.php on line 13