For further code optimisation and checking against the PSR-12 encoding standard, you can add ECS::
https://github.com/symplify/easy-coding-standard

Install composer package:
composer require symplify/easy-coding-standard --dev

Initialise (creates ecs.php in root):
vendor/bin/ecs init

Check your code:
vendor/bin/ecs check packages/zwbisdrei_config

Fix your code:
vendor/bin/ecs check packages/zwbisdrei_config --fix