necessary <inherits> lines for c.g.c.collect.testModule, etc. However, adding <inherits>
            lines could make c.g.c.base.testModule transitively inherit from extra modules. If some
            of those modules are ones that it uses but forgets to list in its own <inherits>, we'd
            like to get an error. Currently we do, but if we add the extra <inherits> lines, we
            won't.