https://github.com/abdullahpazarbasi/design-patterns-in-php/tree/master/GangOfFour/Behavioral/ChainOfResponsibility
https://github.com/abdullahpazarbasi/design-patterns-in-php/tree/master/GangOfFour/Behavioral/Command
https://github.com/abdullahpazarbasi/design-patterns-in-php/tree/master/GangOfFour/Behavioral/ChainOfResponsibility
https://github.com/abdullahpazarbasi/design-patterns-in-php/tree/master/GangOfFour/Behavioral/Command