Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /home/noct-c/www/tanakahashi/vendor/symfony/mime/Tests/MessageConverterTest.php:19 Stack trace: #0 {main} thrown in /home/noct-c/www/tanakahashi/vendor/symfony/mime/Tests/MessageConverterTest.php on line 19