Fatal error: Uncaught Error: Class "Braintree\Collection" not found in C:\xampp\htdocs\public\vendor\braintree\braintree_php\lib\Braintree\Error\ValidationErrorCollection.php:15 Stack trace: #0 {main} thrown in C:\xampp\htdocs\public\vendor\braintree\braintree_php\lib\Braintree\Error\ValidationErrorCollection.php on line 15