Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\impresoraLocal\sistema\clases\vendor\mike42\gfx-php\test\integration\PngsuiteTest.php:13 Stack trace: #0 {main} thrown in C:\xampp\htdocs\impresoraLocal\sistema\clases\vendor\mike42\gfx-php\test\integration\PngsuiteTest.php on line 13