What does your feature entail? What is it for? How will it affect existing workflows or user experience?
Under the selected option have another option called Close Tree except root Tab or similar.

What are the exact ways that you see a user using your proposed feature? Please go into as much detail as possible, and provide examples of how other browsers/apps implement this feature, if applicable. If your feature suggestion adds on to an existing feature, how would it work into it to extend its usefulness?
I open all links in a page, for example for bug/feature reporting, to read them, and then I want to close them, however without having to duplicate the root tab to close the tree safely.