def _describe_command(self, command, **options):
        raise NotImplementedError()
Prepares for switching from old_module_dict to new_module_dict.
dataset/ETHPy150Open sdispater/cleo/cleo/descriptors/descriptor.py/Descriptor._describe_command--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/tools/dev_appserver.py/ConnectAndDisconnectChildModules