Fatal error: Uncaught Error: Class "PHPUnit\Framework\TestCase" not found in /home/mohamma2/public_html/subdomains/vendor/markrogoyski/ipv4-subnet-calculator/tests/SubnetCalculatorWildcardMaskTest.php:18 Stack trace: #0 {main} thrown in /home/mohamma2/public_html/subdomains/vendor/markrogoyski/ipv4-subnet-calculator/tests/SubnetCalculatorWildcardMaskTest.php on line 18