We are using GitHub Actions as a continuous integration system.
For details, see workflows/continuous-integration.yml.
Make sure you have PHP, composer and make installed.
We are using friendsofphp/php-cs-fixer to automatically format the code.
Run the following to display a list of available targets with corresponding descriptions:
make help
Always use class member visibility protected over private. We cannot foresee every
possible use case in advance, extending the code should remain possible.