Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in E:\www\API\mod_send\lib\aliyun-dysms-php-sdk\msg_sdk\tests\Core\Auth\CredentialTest.php:8 Stack trace: #0 {main} thrown in E:\www\API\mod_send\lib\aliyun-dysms-php-sdk\msg_sdk\tests\Core\Auth\CredentialTest.php on line 8