Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in C:\xampp\htdocs\docu_sign\App\vendor\docusign\esign-client\test\UnitTests.php:82 Stack trace: #0 {main} thrown in C:\xampp\htdocs\docu_sign\App\vendor\docusign\esign-client\test\UnitTests.php on line 82