Fatal error: Uncaught Error: Class 'Think\Cache' not found in C:\Project\WWW\SanGuo\ThinkPHP\Library\Think\Cache\Driver\Memcached.class.php:20 Stack trace: #0 {main} thrown in C:\Project\WWW\SanGuo\ThinkPHP\Library\Think\Cache\Driver\Memcached.class.php on line 20