https://lechenie-web.ru/4-%d0%b2%d0%be%d0%b7%d0%bc%d0%be%d0%b6%d0%bd%d0%be%d1%81%d1%82%d0%b8-%d0%bc%d0%b5%d1%82%d0%be%d0%b4%d0%b0/
4. Возможности метода.