Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /data/htmlwww/workspace/web-tubanzhang/vendor/guzzlehttp/guzzle/tests/Exception/SeekExceptionTest.php:8 Stack trace: #0 {main} thrown in /data/htmlwww/workspace/web-tubanzhang/vendor/guzzlehttp/guzzle/tests/Exception/SeekExceptionTest.php on line 8