Yeah, the ``opts_count = int(pop.get(...'))`` bit and a ``for i in range(1, ...): val = pop.get(...)`` part could make a cool generator (i.e. iterator factory) method on the ``Params()`` class.  Usage could be like: give it the name of a count key and a base_name, and it returns an iterator over all the values from params.  I'm sure this could/would be used elsewhere in the virt-test project.  What do you think?