make_dyn_class should memo-ize the dynamically generated classes, and should take a list of keys.

The invocations of make_dyn_class are too wordy. They should be super simple, just one arg which very closely resembles the class name. make_dyn_class should then interpret that one argument.

Need to add into a test that invokes CreatePool.

This is not the correct way to do this. It should really be possible to make dynamic self-generating classes, and that would require working with dbus-python-client-gen.

Obsoleted by the better idea of instantiating the whole class with only the methods needed for that invocation. Would still have to remember to add the absolute path check.