Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /var/www/html/server/vendor/elephantio/elephant.io/test/Payload/EncoderTest.php:19 Stack trace: #0 {main} thrown in /var/www/html/server/vendor/elephantio/elephant.io/test/Payload/EncoderTest.php on line 19