def _subsystem(self, name):
        s = self
        for part in name.split('.'):
            s = s._subsystems[part]
        return s
This method returns a module.
dataset/ETHPy150Open OpenMDAO/OpenMDAO/openmdao/core/group.py/Group._subsystem--crossover with--dataset/ETHPy150Open openstack/compass-core/compass/actions/cli.py/BootCLI.get_module