dgrnbrg/autotest — comment on commit 4401e8351d3bbae61b5f326c8815701b38bf8171
File: server/hosts/site_factory.py line 26
By dgrnbrg:

We don't need to change the inheritance for the way this class is used. Since the type() function is used to construct a new anonymous class with multiple base classes in server/hosts/factory.py, the AsyncSSHMixin is only used as a superclass to an anonymous class that also has SSHHost as a superclass.

I'd argue that the factory/mixin mechanism is very confusing in autotest (it took me a few days to puzzle it out), but it's very flexible and I think it's there to avoid hierarchically coupling dependencies.