I wrote three service units, say a.service b.service and c.service. C requires and runs after b, b requires and runs after a, so when I execute "systemctl start c.service", all three of them will be launched one by one. But when I want to stop all of them, I have to execute "systemctl stop a.service b.service c.service". Is there any other way to stop all of them with less typing? I know with "Bindto=" I can use "systemctl stop a.service" to stop all of them, but what if I got c Bindto a and b, while a and b have no required relationship to each other?