Fatal error: Uncaught Error: Class 'CallbackReference' not found in E:\phpStudy\PHPTutorial\WWW\mk\vendor\electrolinux\phpquery\test-cases\test_events.php:28 Stack trace: #0 {main} thrown in E:\phpStudy\PHPTutorial\WWW\mk\vendor\electrolinux\phpquery\test-cases\test_events.php on line 28