Warning: Undefined variable $container in C:\xampp\htdocs\electronica\vendor\symfony\swiftmailer-bundle\Tests\DependencyInjection\Fixtures\config\php\null.php on line 2

Fatal error: Uncaught Error: Call to a member function loadFromExtension() on null in C:\xampp\htdocs\electronica\vendor\symfony\swiftmailer-bundle\Tests\DependencyInjection\Fixtures\config\php\null.php:2 Stack trace: #0 {main} thrown in C:\xampp\htdocs\electronica\vendor\symfony\swiftmailer-bundle\Tests\DependencyInjection\Fixtures\config\php\null.php on line 2