https://www.zdrojak.cz/clanky/php-v-rytmu-hip-hopu/
https://docs.hhvm.com/hhvm/installation/building-from-source
https://github.com/facebook/hhvm/wiki/_pages
https://medium.com/@AlyShmahell/https-medium-com-alyshmahell-tutorial-how-to-install-hhvm-for-hack-php-development-on-ubuntu-18-04-24cfc11e1e94