Fatal error: Uncaught Error: Class 'PhpOffice\PhpSpreadsheet\Shared\Date' not found in /var/www/html/lib/php-spreadsheet/tests/data/Calculation/Statistical/SLOPE.php:29 Stack trace: #0 {main} thrown in /var/www/html/lib/php-spreadsheet/tests/data/Calculation/Statistical/SLOPE.php on line 29