Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in D:\Webserver\Apache24\htdocs\testephp\signxml\vendor\vanilla\garden-schema\tests\AbstractSchemaTest.php:21 Stack trace: #0 {main} thrown in D:\Webserver\Apache24\htdocs\testephp\signxml\vendor\vanilla\garden-schema\tests\AbstractSchemaTest.php on line 21