Fatal error: Uncaught Error: Class 'PHPUnit\Framework\TestCase' not found in /var/www/html/lib/php-spreadsheet/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericLoadTest.php:15 Stack trace: #0 {main} thrown in /var/www/html/lib/php-spreadsheet/tests/PhpSpreadsheetTests/Reader/Gnumeric/GnumericLoadTest.php on line 15